/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Miika Hämäläinen
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/blenkernel/intern/dynamicpaint.c
 *  \ingroup bke
 */

#include "MEM_guardedalloc.h"

#include <math.h>
#include <stdio.h>

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_kdtree.h"
#include "BLI_threads.h"
#include "BLI_utildefines.h"

#include "BLT_translation.h"

#include "DNA_anim_types.h"
#include "DNA_armature_types.h"
#include "DNA_constraint_types.h"
#include "DNA_dynamicpaint_types.h"
#include "DNA_group_types.h" /*GroupObject*/
#include "DNA_material_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_modifier_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "DNA_texture_types.h"

#include "BKE_animsys.h"
#include "BKE_armature.h"
#include "BKE_bvhutils.h"   /* bvh tree	*/
#include "BKE_cdderivedmesh.h"
#include "BKE_constraint.h"
#include "BKE_customdata.h"
#include "BKE_deform.h"
#include "BKE_DerivedMesh.h"
#include "BKE_dynamicpaint.h"
#include "BKE_effect.h"
#include "BKE_global.h"
#include "BKE_image.h"
#include "BKE_main.h"
#include "BKE_material.h"
#include "BKE_modifier.h"
#include "BKE_object.h"
#include "BKE_particle.h"
#include "BKE_pointcache.h"
#include "BKE_scene.h"
#include "BKE_texture.h"

/* for image output	*/
#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"

/* to read material/texture color	*/
#include "RE_render_ext.h"
#include "RE_shader_ext.h"

#ifdef _OPENMP
#  include <omp.h>
#endif

/* could enable at some point but for now there are far too many conversions */
#ifdef __GNUC__
#  pragma GCC diagnostic ignored "-Wdouble-promotion"
#endif

/* precalculated gaussian factors for 5x super sampling	*/
static const float gaussianFactors[5] = {
    0.996849f,
    0.596145f,
    0.596145f,
    0.596145f,
    0.524141f};
static const float gaussianTotal = 3.309425f;

/* UV Image neighboring pixel table x and y list */
static int neighX[8] = {1, 1, 0, -1, -1, -1, 0, 1};
static int neighY[8] = {0, 1, 1, 1, 0, -1, -1, -1};

/* subframe_updateObject() flags */
#define SUBFRAME_RECURSION 5
#define UPDATE_MESH (1 << 1)
#define UPDATE_EVERYTHING (UPDATE_MESH) // | UPDATE_PARENTS
/* surface_getBrushFlags() return vals */
#define BRUSH_USES_VELOCITY (1 << 0)
/* brush mesh raycast status */
#define HIT_VOLUME 1
#define HIT_PROXIMITY 2
/* dynamicPaint_findNeighbourPixel() return codes */
#define NOT_FOUND -1
#define ON_MESH_EDGE -2
#define OUT_OF_TEXTURE -3
/* paint effect default movement per frame in global units */
#define EFF_MOVEMENT_PER_FRAME 0.05f
/* initial wave time factor */
#define WAVE_TIME_FAC (1.0f / 24.f)
#define CANVAS_REL_SIZE 5.0f
/* drying limits */
#define MIN_WETNESS 0.001f
#define MAX_WETNESS 5.0f


/* dissolve inline function */
BLI_INLINE void value_dissolve(float *r_value, const float time, const float scale, const int is_log)
{
	*r_value = (is_log) ?
	              (*r_value) * (powf(MIN_WETNESS, 1.0f / (1.2f * time / scale))) :
	              (*r_value) - 1.0f / time * scale;
}


/***************************** Internal Structs ***************************/

typedef struct Bounds2D {
	float min[2], max[2];
} Bounds2D;

typedef struct Bounds3D {
	int valid;
	float min[3], max[3];
} Bounds3D;

typedef struct VolumeGrid {
	int dim[3];
	Bounds3D grid_bounds; /* whole grid bounds */

	Bounds3D *bounds;   /* (x*y*z) precalculated grid cell bounds */
	int *s_pos; /* (x*y*z) t_index begin id */
	int *s_num; /* (x*y*z) number of t_index points */
	int *t_index; /* actual surface point index,
	               * access: (s_pos+s_num) */
} VolumeGrid;

typedef struct Vec3f {
	float v[3];
} Vec3f;

typedef struct BakeAdjPoint {
	float dir[3];   /* vector pointing towards this neighbor */
	float dist;     /* distance to */
} BakeAdjPoint;

/* Surface data used while processing a frame	*/
typedef struct PaintBakeNormal {
	float invNorm[3];  /* current pixel world-space inverted normal */
	float normal_scale; /* normal directional scale for displace mapping */
} PaintBakeNormal;

/* Temp surface data used to process a frame */
typedef struct PaintBakeData {
	/* point space data */
	PaintBakeNormal *bNormal;
	int *s_pos; /* index to start reading point sample realCoord */
	int *s_num; /* num of realCoord samples */
	Vec3f *realCoord;  /* current pixel center world-space coordinates for each sample
	                    *  ordered as (s_pos+s_num)*/
	Bounds3D mesh_bounds;

	/* adjacency info */
	BakeAdjPoint *bNeighs; /* current global neighbor distances and directions, if required */
	double average_dist;
	/* space partitioning */
	VolumeGrid *grid;       /* space partitioning grid to optimize brush checks */

	/* velocity and movement */
	Vec3f *velocity;        /* speed vector in global space movement per frame, if required */
	Vec3f *prev_velocity;
	float *brush_velocity;  /* special temp data for post-p velocity based brushes like smudge
	                         *  3 float dir vec + 1 float str */
	MVert *prev_verts;      /* copy of previous frame vertices. used to observe surface movement */
	float prev_obmat[4][4]; /* previous frame object matrix */
	int clear;              /* flag to check if surface was cleared/reset -> have to redo velocity etc. */

} PaintBakeData;

/* UV Image sequence format point	*/
typedef struct PaintUVPoint {
	/* Pixel / mesh data */
	unsigned int tri_index, pixel_index;    /* tri index on domain derived mesh */
	unsigned int v1, v2, v3;                /* vertex indexes */

	unsigned int neighbour_pixel;   /* If this pixel isn't uv mapped to any face,
	                                 * but it's neighboring pixel is */
} PaintUVPoint;

typedef struct ImgSeqFormatData {
	PaintUVPoint *uv_p;
	Vec3f *barycentricWeights;      /* b-weights for all pixel samples */
} ImgSeqFormatData;

/* adjacency data flags */
#define ADJ_ON_MESH_EDGE (1 << 0)

typedef struct PaintAdjData {
	int *n_target;  /* array of neighboring point indexes,
	                 * for single sample use (n_index + neigh_num) */
	int *n_index;   /* index to start reading n_target for each point */
	int *n_num;     /* num of neighs for each point */
	int *flags;     /* vertex adjacency flags */
	int total_targets; /* size of n_target */
} PaintAdjData;

/***************************** General Utils ******************************/

/* Set canvas error string to display at the bake report */
static int setError(DynamicPaintCanvasSettings *canvas, const char *string)
{
	/* Add error to canvas ui info label */
	BLI_strncpy(canvas->error, string, sizeof(canvas->error));
	return 0;
}

/* Get number of surface points for cached types */
static int dynamicPaint_surfaceNumOfPoints(DynamicPaintSurface *surface)
{
	if (surface->format == MOD_DPAINT_SURFACE_F_PTEX) {
		return 0; /* not supported atm */
	}
	else if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
		if (!surface->canvas->dm) return 0;  /* invalid derived mesh */
		return surface->canvas->dm->getNumVerts(surface->canvas->dm);
	}
	else
		return 0;
}

/* checks whether surface's format/type has realtime preview */
bool dynamicPaint_surfaceHasColorPreview(DynamicPaintSurface *surface)
{
	if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
		return false;
	}
	else if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
		if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE ||
		    surface->type == MOD_DPAINT_SURFACE_T_WAVE)
		{
			return false;
		}
		else {
			return true;
		}
	}
	else {
		return true;
	}
}

/* get currently active surface (in user interface) */
DynamicPaintSurface *get_activeSurface(DynamicPaintCanvasSettings *canvas)
{
	DynamicPaintSurface *surface = canvas->surfaces.first;
	int i;

	for (i = 0; surface; surface = surface->next) {
		if (i == canvas->active_sur)
			return surface;
		i++;
	}
	return NULL;
}

/* set preview to first previewable surface */
void dynamicPaint_resetPreview(DynamicPaintCanvasSettings *canvas)
{
	DynamicPaintSurface *surface = canvas->surfaces.first;
	bool done = false;

	for (; surface; surface = surface->next) {
		if (!done && dynamicPaint_surfaceHasColorPreview(surface)) {
			surface->flags |= MOD_DPAINT_PREVIEW;
			done = true;
		}
		else
			surface->flags &= ~MOD_DPAINT_PREVIEW;
	}
}

/* set preview to defined surface */
static void dynamicPaint_setPreview(DynamicPaintSurface *t_surface)
{
	DynamicPaintSurface *surface = t_surface->canvas->surfaces.first;
	for (; surface; surface = surface->next) {
		if (surface == t_surface)
			surface->flags |= MOD_DPAINT_PREVIEW;
		else
			surface->flags &= ~MOD_DPAINT_PREVIEW;
	}
}

bool dynamicPaint_outputLayerExists(struct DynamicPaintSurface *surface, Object *ob, int output)
{
	const char *name;

	if (output == 0)
		name = surface->output_name;
	else if (output == 1)
		name = surface->output_name2;
	else
		return false;

	if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
		if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
			Mesh *me = ob->data;
			return (CustomData_get_named_layer_index(&me->ldata, CD_MLOOPCOL, name) != -1);
		}
		else if (surface->type == MOD_DPAINT_SURFACE_T_WEIGHT)
			return (defgroup_name_index(ob, surface->output_name) != -1);
	}

	return false;
}

static bool surface_duplicateOutputExists(void *arg, const char *name)
{
	DynamicPaintSurface *t_surface = (DynamicPaintSurface *)arg;
	DynamicPaintSurface *surface = t_surface->canvas->surfaces.first;

	for (; surface; surface = surface->next) {
		if (surface != t_surface && surface->type == t_surface->type &&
		    surface->format == t_surface->format)
		{
			if (surface->output_name[0] != '\0' && !BLI_path_cmp(name, surface->output_name)) return true;
			if (surface->output_name2[0] != '\0' && !BLI_path_cmp(name, surface->output_name2)) return true;
		}
	}
	return false;
}

static void surface_setUniqueOutputName(DynamicPaintSurface *surface, char *basename, int output)
{
	char name[64];
	BLI_strncpy(name, basename, sizeof(name)); /* in case basename is surface->name use a copy */
	if (!output)
		BLI_uniquename_cb(surface_duplicateOutputExists, surface, name, '.', surface->output_name, sizeof(surface->output_name));
	if (output)
		BLI_uniquename_cb(surface_duplicateOutputExists, surface, name, '.', surface->output_name2, sizeof(surface->output_name2));
}


static bool surface_duplicateNameExists(void *arg, const char *name)
{
	DynamicPaintSurface *t_surface = (DynamicPaintSurface *)arg;
	DynamicPaintSurface *surface = t_surface->canvas->surfaces.first;

	for (; surface; surface = surface->next) {
		if (surface != t_surface && STREQ(name, surface->name)) return true;
	}
	return false;
}

void dynamicPaintSurface_setUniqueName(DynamicPaintSurface *surface, const char *basename)
{
	char name[64];
	BLI_strncpy(name, basename, sizeof(name)); /* in case basename is surface->name use a copy */
	BLI_uniquename_cb(surface_duplicateNameExists, surface, name, '.', surface->name, sizeof(surface->name));
}


/* change surface data to defaults on new type */
void dynamicPaintSurface_updateType(struct DynamicPaintSurface *surface)
{
	if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
		surface->output_name[0] = '\0';
		surface->output_name2[0] = '\0';
		surface->flags |= MOD_DPAINT_ANTIALIAS;
		surface->depth_clamp = 1.0f;
	}
	else {
		strcpy(surface->output_name, "dp_");
		BLI_strncpy(surface->output_name2, surface->output_name, sizeof(surface->output_name2));
		surface->flags &= ~MOD_DPAINT_ANTIALIAS;
		surface->depth_clamp = 0.0f;
	}

	if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
		strcat(surface->output_name, "paintmap");
		strcat(surface->output_name2, "wetmap");
		surface_setUniqueOutputName(surface, surface->output_name2, 1);
	}
	else if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE) {
		strcat(surface->output_name, "displace");
	}
	else if (surface->type == MOD_DPAINT_SURFACE_T_WEIGHT) {
		strcat(surface->output_name, "weight");
	}
	else if (surface->type == MOD_DPAINT_SURFACE_T_WAVE) {
		strcat(surface->output_name, "wave");
	}

	surface_setUniqueOutputName(surface, surface->output_name, 0);

	/* update preview */
	if (dynamicPaint_surfaceHasColorPreview(surface))
		dynamicPaint_setPreview(surface);
	else
		dynamicPaint_resetPreview(surface->canvas);
}

static int surface_totalSamples(DynamicPaintSurface *surface)
{
	if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ &&
	    surface->flags & MOD_DPAINT_ANTIALIAS)
	{
		return (surface->data->total_points * 5);
	}
	if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX &&
	    surface->flags & MOD_DPAINT_ANTIALIAS && surface->data->adj_data)
	{
		return (surface->data->total_points + surface->data->adj_data->total_targets);
	}

	return surface->data->total_points;
}

static void blendColors(const float t_color[3], float t_alpha, const float s_color[3], float s_alpha, float result[4])
{
	int i;
	float i_alpha = 1.0f - s_alpha;
	float f_alpha = t_alpha * i_alpha + s_alpha;

	/* blend colors */
	if (f_alpha) {
		for (i = 0; i < 3; i++) {
			result[i] = (t_color[i] * t_alpha * i_alpha + s_color[i] * s_alpha) / f_alpha;
		}
	}
	else {
		copy_v3_v3(result, t_color);
	}
	/* return final alpha */
	result[3] = f_alpha;
}

/* Mix two alpha weighed colors by a defined ratio. output is saved at a_color */
static float mixColors(float a_color[3], float a_weight, const float b_color[3], float b_weight, float ratio)
{
	float weight_ratio, factor;
	if (b_weight) {
		/* if first value has no weight just use b_color */
		if (!a_weight) {
			copy_v3_v3(a_color, b_color);
			return b_weight * ratio;
		}
		weight_ratio = b_weight / (a_weight + b_weight);
	}
	else {
		return a_weight * (1.0f - ratio);
	}

	/* calculate final interpolation factor */
	if (ratio <= 0.5f) {
		factor = weight_ratio * (ratio * 2.0f);
	}
	else {
		ratio = (ratio * 2.0f - 1.0f);
		factor = weight_ratio * (1.0f - ratio) + ratio;
	}
	/* mix final color */
	interp_v3_v3v3(a_color, a_color, b_color, factor);
	return (1.0f - factor) * a_weight + factor * b_weight;
}

/* set "ignore cache" flag for all caches on this object */
static void object_cacheIgnoreClear(Object *ob, int state)
{
	ListBase pidlist;
	PTCacheID *pid;
	BKE_ptcache_ids_from_object(&pidlist, ob, NULL, 0);

	for (pid = pidlist.first; pid; pid = pid->next) {
		if (pid->cache) {
			if (state)
				pid->cache->flag |= PTCACHE_IGNORE_CLEAR;
			else
				pid->cache->flag &= ~PTCACHE_IGNORE_CLEAR;
		}
	}

	BLI_freelistN(&pidlist);
}

static int subframe_updateObject(Scene *scene, Object *ob, int flags, int parent_recursion, float frame)
{
	DynamicPaintModifierData *pmd = (DynamicPaintModifierData *)modifiers_findByType(ob, eModifierType_DynamicPaint);
	bConstraint *con;

	/* if other is dynamic paint canvas, don't update */
	if (pmd && pmd->canvas)
		return 1;

	/* if object has parents, update them too */
	if (parent_recursion) {
		int recursion = parent_recursion - 1;
		int is_canvas = 0;
		if (ob->parent) is_canvas += subframe_updateObject(scene, ob->parent, 0, recursion, frame);
		if (ob->track) is_canvas += subframe_updateObject(scene, ob->track, 0, recursion, frame);

		/* skip subframe if object is parented
		 *  to vertex of a dynamic paint canvas */
		if (is_canvas && (ob->partype == PARVERT1 || ob->partype == PARVERT3))
			return 0;

		/* also update constraint targets */
		for (con = ob->constraints.first; con; con = con->next) {
			const bConstraintTypeInfo *cti = BKE_constraint_typeinfo_get(con);
			ListBase targets = {NULL, NULL};

			if (cti && cti->get_constraint_targets) {
				bConstraintTarget *ct;
				cti->get_constraint_targets(con, &targets);
				for (ct = targets.first; ct; ct = ct->next) {
					if (ct->tar)
						subframe_updateObject(scene, ct->tar, 0, recursion, frame);
				}
				/* free temp targets */
				if (cti->flush_constraint_targets)
					cti->flush_constraint_targets(con, &targets, 0);
			}
		}
	}

	/* was originally OB_RECALC_ALL - TODO - which flags are really needed??? */
	ob->recalc |= OB_RECALC_OB | OB_RECALC_DATA | OB_RECALC_TIME;
	BKE_animsys_evaluate_animdata(scene, &ob->id, ob->adt, frame, ADT_RECALC_ANIM);
	if (flags & UPDATE_MESH) {
		/* ignore cache clear during subframe updates
		 *  to not mess up cache validity */
		object_cacheIgnoreClear(ob, 1);
		BKE_object_handle_update(G.main->eval_ctx, scene, ob);
		object_cacheIgnoreClear(ob, 0);
	}
	else
		BKE_object_where_is_calc_time(scene, ob, frame);

	/* for curve following objects, parented curve has to be updated too */
	if (ob->type == OB_CURVE) {
		Curve *cu = ob->data;
		BKE_animsys_evaluate_animdata(scene, &cu->id, cu->adt, frame, ADT_RECALC_ANIM);
	}
	/* and armatures... */
	if (ob->type == OB_ARMATURE) {
		bArmature *arm = ob->data;
		BKE_animsys_evaluate_animdata(scene, &arm->id, arm->adt, frame, ADT_RECALC_ANIM);
		BKE_pose_where_is(scene, ob);
	}

	return 0;
}

static void scene_setSubframe(Scene *scene, float subframe)
{
	/* dynamic paint subframes must be done on previous frame */
	scene->r.cfra -= 1;
	scene->r.subframe = subframe;
}

static int surface_getBrushFlags(DynamicPaintSurface *surface, const Scene *scene)
{
	Base *base = NULL;
	GroupObject *go = NULL;
	Object *brushObj = NULL;
	ModifierData *md = NULL;

	int flags = 0;

	if (surface->brush_group)
		go = surface->brush_group->gobject.first;
	else
		base = scene->base.first;

	while (base || go) {
		brushObj = NULL;

		/* select object */
		if (surface->brush_group) {
			if (go->ob) brushObj = go->ob;
		}
		else
			brushObj = base->object;

		if (!brushObj) {
			if (surface->brush_group) go = go->next;
			else base = base->next;
			continue;
		}

		if (surface->brush_group)
			go = go->next;
		else
			base = base->next;

		md = modifiers_findByType(brushObj, eModifierType_DynamicPaint);
		if (md && md->mode & (eModifierMode_Realtime | eModifierMode_Render)) {
			DynamicPaintModifierData *pmd2 = (DynamicPaintModifierData *)md;

			if (pmd2->brush) {
				DynamicPaintBrushSettings *brush = pmd2->brush;

				if (brush->flags & MOD_DPAINT_USES_VELOCITY)
					flags |= BRUSH_USES_VELOCITY;
			}
		}
	}

	return flags;
}

static int brush_usesMaterial(DynamicPaintBrushSettings *brush, Scene *scene)
{
	return ((brush->flags & MOD_DPAINT_USE_MATERIAL) && (!BKE_scene_use_new_shading_nodes(scene)));
}

/* check whether two bounds intersect */
static int boundsIntersect(Bounds3D *b1, Bounds3D *b2)
{
	int i = 2;
	if (!b1->valid || !b2->valid) return 0;
	for (; i >= 0; i -= 1)
		if (!(b1->min[i] <= b2->max[i] && b1->max[i] >= b2->min[i])) return 0;
	return 1;
}

/* check whether two bounds intersect inside defined proximity */
static int boundsIntersectDist(Bounds3D *b1, Bounds3D *b2, float dist)
{
	int i = 2;
	if (!b1->valid || !b2->valid) return 0;
	for (; i >= 0; i -= 1)
		if (!(b1->min[i] <= (b2->max[i] + dist) && b1->max[i] >= (b2->min[i] - dist))) return 0;
	return 1;
}

/* check whether bounds intersects a point with given radius */
static int boundIntersectPoint(Bounds3D *b, float point[3], float radius)
{
	int i = 2;
	if (!b->valid) return 0;
	for (; i >= 0; i -= 1)
		if (!(b->min[i] <= (point[i] + radius) && b->max[i] >= (point[i] - radius))) return 0;
	return 1;
}

/* expand bounds by a new point */
static void boundInsert(Bounds3D *b, float point[3])
{
	int i = 2;
	if (!b->valid) {
		copy_v3_v3(b->min, point);
		copy_v3_v3(b->max, point);
		b->valid = 1;
	}
	else {
		for (; i >= 0; i -= 1) {
			if (point[i] < b->min[i]) b->min[i] = point[i];
			if (point[i] > b->max[i]) b->max[i] = point[i];
		}
	}
}

static float getSurfaceDimension(PaintSurfaceData *sData)
{
	Bounds3D *mb = &sData->bData->mesh_bounds;
	return max_fff((mb->max[0] - mb->min[0]), (mb->max[1] - mb->min[1]), (mb->max[2] - mb->min[2]));
}

static void freeGrid(PaintSurfaceData *data)
{
	PaintBakeData *bData = data->bData;
	VolumeGrid *grid = bData->grid;

	if (grid->bounds) MEM_freeN(grid->bounds);
	if (grid->s_pos) MEM_freeN(grid->s_pos);
	if (grid->s_num) MEM_freeN(grid->s_num);
	if (grid->t_index) MEM_freeN(grid->t_index);

	MEM_freeN(bData->grid);
	bData->grid = NULL;
}

static void surfaceGenerateGrid(struct DynamicPaintSurface *surface)
{
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	Bounds3D *grid_bounds;
	VolumeGrid *grid;
	int grid_cells, axis = 3;
	int *temp_t_index = NULL;
	int *temp_s_num = NULL;

#ifdef _OPENMP
	int num_of_threads = omp_get_max_threads();
#else
	int num_of_threads = 1;
#endif

	if (bData->grid)
		freeGrid(sData);

	/* allocate separate bounds for each thread */
	grid_bounds = MEM_callocN(sizeof(Bounds3D) * num_of_threads, "Grid Bounds");
	bData->grid = MEM_callocN(sizeof(VolumeGrid), "Surface Grid");
	grid = bData->grid;

	if (grid && grid_bounds) {
		int i, error = 0;
		float dim_factor, volume, dim[3];
		float td[3];
		float min_dim;

		/* calculate canvas dimensions */
#pragma omp parallel for schedule(static)
		for (i = 0; i < sData->total_points; i++) {
#ifdef _OPENMP
			int id = omp_get_thread_num();
			boundInsert(&grid_bounds[id], (bData->realCoord[bData->s_pos[i]].v));
#else
			boundInsert(&grid_bounds[0], (bData->realCoord[bData->s_pos[i]].v));
#endif
		}

		/* get final dimensions */
		for (i = 0; i < num_of_threads; i++) {
			boundInsert(&grid->grid_bounds, grid_bounds[i].min);
			boundInsert(&grid->grid_bounds, grid_bounds[i].max);
		}

		/* get dimensions */
		sub_v3_v3v3(dim, grid->grid_bounds.max, grid->grid_bounds.min);
		copy_v3_v3(td, dim);
		min_dim = max_fff(td[0], td[1], td[2]) / 1000.f;

		/* deactivate zero axises */
		for (i = 0; i < 3; i++) {
			if (td[i] < min_dim) { td[i] = 1.0f; axis -= 1; }
		}

		if (axis == 0 || max_fff(td[0], td[1], td[2]) < 0.0001f) {
			MEM_freeN(grid_bounds);
			MEM_freeN(bData->grid);
			bData->grid = NULL;
			return;
		}

		/* now calculate grid volume/area/width depending on num of active axis */
		volume = td[0] * td[1] * td[2];

		/* determine final grid size by trying to fit average 10.000 points per grid cell */
		dim_factor = (float)pow((double)volume / ((double)sData->total_points / 10000.0), 1.0 / (double)axis);

		/* define final grid size using dim_factor, use min 3 for active axises */
		for (i = 0; i < 3; i++) {
			grid->dim[i] = (int)floor(td[i] / dim_factor);
			CLAMP(grid->dim[i], (dim[i] >= min_dim) ? 3 : 1, 100);
		}
		grid_cells = grid->dim[0] * grid->dim[1] * grid->dim[2];

		/* allocate memory for grids */
		grid->bounds = MEM_callocN(sizeof(Bounds3D) * grid_cells, "Surface Grid Bounds");
		grid->s_pos = MEM_callocN(sizeof(int) * grid_cells, "Surface Grid Position");
		grid->s_num = MEM_callocN(sizeof(int) * grid_cells * num_of_threads, "Surface Grid Points");
		temp_s_num = MEM_callocN(sizeof(int) * grid_cells, "Temp Surface Grid Points");
		grid->t_index = MEM_callocN(sizeof(int) * sData->total_points, "Surface Grid Target Ids");
		temp_t_index = MEM_callocN(sizeof(int) * sData->total_points, "Temp Surface Grid Target Ids");

		/* in case of an allocation failure abort here */
		if (!grid->bounds || !grid->s_pos || !grid->s_num || !grid->t_index || !temp_s_num || !temp_t_index)
			error = 1;

		if (!error) {
			/* calculate number of points withing each cell */
#pragma omp parallel for schedule(static)
			for (i = 0; i < sData->total_points; i++) {
				int co[3], j;
				for (j = 0; j < 3; j++) {
					co[j] = (int)floor((bData->realCoord[bData->s_pos[i]].v[j] - grid->grid_bounds.min[j]) / dim[j] * grid->dim[j]);
					CLAMP(co[j], 0, grid->dim[j] - 1);
				}

				temp_t_index[i] = co[0] + co[1] * grid->dim[0] + co[2] * grid->dim[0] * grid->dim[1];
#ifdef _OPENMP
				grid->s_num[temp_t_index[i] + omp_get_thread_num() * grid_cells]++;
#else
				grid->s_num[temp_t_index[i]]++;
#endif
			}

			/* for first cell only calc s_num */
			for (i = 1; i < num_of_threads; i++) {
				grid->s_num[0] += grid->s_num[i * grid_cells];
			}

			/* calculate grid indexes */
			for (i = 1; i < grid_cells; i++) {
				int id;
				for (id = 1; id < num_of_threads; id++) {
					grid->s_num[i] += grid->s_num[i + id * grid_cells];
				}
				grid->s_pos[i] = grid->s_pos[i - 1] + grid->s_num[i - 1];
			}

			/* save point indexes to final array */
			for (i = 0; i < sData->total_points; i++) {
				int pos = grid->s_pos[temp_t_index[i]] + temp_s_num[temp_t_index[i]];
				grid->t_index[pos] = i;

				temp_s_num[temp_t_index[i]]++;
			}

			/* calculate cell bounds */
			{
				int x;
#pragma omp parallel for schedule(static)
				for (x = 0; x < grid->dim[0]; x++) {
					int y;
					for (y = 0; y < grid->dim[1]; y++) {
						int z;
						for (z = 0; z < grid->dim[2]; z++) {
							int j, b_index = x + y * grid->dim[0] + z * grid->dim[0] * grid->dim[1];
							/* set bounds */
							for (j = 0; j < 3; j++) {
								int s = (j == 0) ? x : ((j == 1) ? y : z);
								grid->bounds[b_index].min[j] = grid->grid_bounds.min[j] + dim[j] / grid->dim[j] * s;
								grid->bounds[b_index].max[j] = grid->grid_bounds.min[j] + dim[j] / grid->dim[j] * (s + 1);
							}
							grid->bounds[b_index].valid = 1;
						}
					}
				}
			}
		}

		if (temp_s_num) MEM_freeN(temp_s_num);
		if (temp_t_index) MEM_freeN(temp_t_index);

		/* free per thread s_num values */
		grid->s_num = MEM_reallocN(grid->s_num, sizeof(int) * grid_cells);

		if (error || !grid->s_num) {
			setError(surface->canvas, N_("Not enough free memory"));
			freeGrid(sData);
		}
	}

	if (grid_bounds) MEM_freeN(grid_bounds);
}

/***************************** Freeing data ******************************/

/* Free brush data */
void dynamicPaint_freeBrush(struct DynamicPaintModifierData *pmd)
{
	if (pmd->brush) {
		if (pmd->brush->dm)
			pmd->brush->dm->release(pmd->brush->dm);
		pmd->brush->dm = NULL;

		if (pmd->brush->paint_ramp)
			MEM_freeN(pmd->brush->paint_ramp);
		pmd->brush->paint_ramp = NULL;
		if (pmd->brush->vel_ramp)
			MEM_freeN(pmd->brush->vel_ramp);
		pmd->brush->vel_ramp = NULL;

		MEM_freeN(pmd->brush);
		pmd->brush = NULL;
	}
}

static void dynamicPaint_freeAdjData(PaintSurfaceData *data)
{
	if (data->adj_data) {
		if (data->adj_data->n_index) MEM_freeN(data->adj_data->n_index);
		if (data->adj_data->n_num) MEM_freeN(data->adj_data->n_num);
		if (data->adj_data->n_target) MEM_freeN(data->adj_data->n_target);
		if (data->adj_data->flags) MEM_freeN(data->adj_data->flags);
		MEM_freeN(data->adj_data);
		data->adj_data = NULL;
	}
}

static void free_bakeData(PaintSurfaceData *data)
{
	PaintBakeData *bData = data->bData;
	if (bData) {
		if (bData->bNormal) MEM_freeN(bData->bNormal);
		if (bData->s_pos) MEM_freeN(bData->s_pos);
		if (bData->s_num) MEM_freeN(bData->s_num);
		if (bData->realCoord) MEM_freeN(bData->realCoord);
		if (bData->bNeighs) MEM_freeN(bData->bNeighs);
		if (bData->grid) freeGrid(data);
		if (bData->prev_verts) MEM_freeN(bData->prev_verts);
		if (bData->velocity) MEM_freeN(bData->velocity);
		if (bData->prev_velocity) MEM_freeN(bData->prev_velocity);

		MEM_freeN(data->bData);
		data->bData = NULL;
	}
}

/* free surface data if it's not used anymore */
static void surface_freeUnusedData(DynamicPaintSurface *surface)
{
	if (!surface->data) return;

	/* free bakedata if not active or surface is baked */
	if (!(surface->flags & MOD_DPAINT_ACTIVE) ||
	    (surface->pointcache && surface->pointcache->flag & PTCACHE_BAKED))
	{
		free_bakeData(surface->data);
	}
}

void dynamicPaint_freeSurfaceData(DynamicPaintSurface *surface)
{
	PaintSurfaceData *data = surface->data;
	if (!data) return;
	if (data->format_data) {
		/* format specific free */
		if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
			ImgSeqFormatData *format_data = (ImgSeqFormatData *)data->format_data;
			if (format_data->uv_p)
				MEM_freeN(format_data->uv_p);
			if (format_data->barycentricWeights)
				MEM_freeN(format_data->barycentricWeights);
		}
		MEM_freeN(data->format_data);
	}
	/* type data */
	if (data->type_data) MEM_freeN(data->type_data);
	dynamicPaint_freeAdjData(data);
	/* bake data */
	free_bakeData(data);

	MEM_freeN(surface->data);
	surface->data = NULL;
}

void dynamicPaint_freeSurface(DynamicPaintSurface *surface)
{
	/* point cache */
	BKE_ptcache_free_list(&(surface->ptcaches));
	surface->pointcache = NULL;

	if (surface->effector_weights)
		MEM_freeN(surface->effector_weights);
	surface->effector_weights = NULL;

	BLI_remlink(&(surface->canvas->surfaces), surface);
	dynamicPaint_freeSurfaceData(surface);
	MEM_freeN(surface);
}

/* Free canvas data */
void dynamicPaint_freeCanvas(DynamicPaintModifierData *pmd)
{
	if (pmd->canvas) {
		/* Free surface data */
		DynamicPaintSurface *surface = pmd->canvas->surfaces.first;
		DynamicPaintSurface *next_surface = NULL;

		while (surface) {
			next_surface = surface->next;
			dynamicPaint_freeSurface(surface);
			surface = next_surface;
		}

		/* free dm copy */
		if (pmd->canvas->dm)
			pmd->canvas->dm->release(pmd->canvas->dm);
		pmd->canvas->dm = NULL;

		MEM_freeN(pmd->canvas);
		pmd->canvas = NULL;
	}
}

/* Free whole dp modifier */
void dynamicPaint_Modifier_free(struct DynamicPaintModifierData *pmd)
{
	if (pmd) {
		dynamicPaint_freeCanvas(pmd);
		dynamicPaint_freeBrush(pmd);
	}
}


/***************************** Initialize and reset ******************************/

/*
 * Creates a new surface and adds it to the list
 * If scene is null, frame range of 1-250 is used
 * A pointer to this surface is returned
 */
DynamicPaintSurface *dynamicPaint_createNewSurface(DynamicPaintCanvasSettings *canvas, Scene *scene)
{
	DynamicPaintSurface *surface = MEM_callocN(sizeof(DynamicPaintSurface), "DynamicPaintSurface");
	if (!surface)
		return NULL;

	surface->canvas = canvas;
	surface->format = MOD_DPAINT_SURFACE_F_VERTEX;
	surface->type = MOD_DPAINT_SURFACE_T_PAINT;

	/* cache */
	surface->pointcache = BKE_ptcache_add(&(surface->ptcaches));
	surface->pointcache->flag |= PTCACHE_DISK_CACHE;
	surface->pointcache->step = 1;

	/* Set initial values */
	surface->flags = MOD_DPAINT_ANTIALIAS | MOD_DPAINT_MULALPHA | MOD_DPAINT_DRY_LOG | MOD_DPAINT_DISSOLVE_LOG |
	                 MOD_DPAINT_ACTIVE | MOD_DPAINT_PREVIEW | MOD_DPAINT_OUT1 | MOD_DPAINT_USE_DRYING;
	surface->effect = 0;
	surface->effect_ui = 1;

	surface->diss_speed = 250;
	surface->dry_speed = 500;
	surface->color_dry_threshold = 1.0f;
	surface->depth_clamp = 0.0f;
	surface->disp_factor = 1.0f;
	surface->disp_type = MOD_DPAINT_DISP_DISPLACE;
	surface->image_fileformat = MOD_DPAINT_IMGFORMAT_PNG;

	surface->influence_scale = 1.0f;
	surface->radius_scale = 1.0f;

	surface->init_color[0] = 1.0f;
	surface->init_color[1] = 1.0f;
	surface->init_color[2] = 1.0f;
	surface->init_color[3] = 1.0f;

	surface->image_resolution = 256;
	surface->substeps = 0;

	if (scene) {
		surface->start_frame = scene->r.sfra;
		surface->end_frame = scene->r.efra;
	}
	else {
		surface->start_frame = 1;
		surface->end_frame = 250;
	}

	surface->spread_speed = 1.0f;
	surface->color_spread_speed = 1.0f;
	surface->shrink_speed = 1.0f;

	surface->wave_damping = 0.04f;
	surface->wave_speed = 1.0f;
	surface->wave_timescale = 1.0f;
	surface->wave_spring = 0.20f;
	surface->wave_smoothness = 1.0f;

	modifier_path_init(surface->image_output_path, sizeof(surface->image_output_path), "cache_dynamicpaint");

	/* Using ID_BRUSH i18n context, as we have no physics/dpaint one for now... */
	dynamicPaintSurface_setUniqueName(surface, CTX_DATA_(BLT_I18NCONTEXT_ID_BRUSH, "Surface"));

	surface->effector_weights = BKE_add_effector_weights(NULL);

	dynamicPaintSurface_updateType(surface);

	BLI_addtail(&canvas->surfaces, surface);

	return surface;
}

/*
 * Initialize modifier data
 */
bool dynamicPaint_createType(struct DynamicPaintModifierData *pmd, int type, struct Scene *scene)
{
	if (pmd) {
		if (type == MOD_DYNAMICPAINT_TYPE_CANVAS) {
			DynamicPaintCanvasSettings *canvas;
			if (pmd->canvas)
				dynamicPaint_freeCanvas(pmd);

			canvas = pmd->canvas = MEM_callocN(sizeof(DynamicPaintCanvasSettings), "DynamicPaint Canvas");
			if (!canvas)
				return false;
			canvas->pmd = pmd;
			canvas->dm = NULL;

			/* Create one surface */
			if (!dynamicPaint_createNewSurface(canvas, scene))
				return false;

		}
		else if (type == MOD_DYNAMICPAINT_TYPE_BRUSH) {
			DynamicPaintBrushSettings *brush;
			if (pmd->brush)
				dynamicPaint_freeBrush(pmd);

			brush = pmd->brush = MEM_callocN(sizeof(DynamicPaintBrushSettings), "DynamicPaint Paint");
			if (!brush)
				return false;
			brush->pmd = pmd;

			brush->psys = NULL;

			brush->flags = MOD_DPAINT_ABS_ALPHA | MOD_DPAINT_RAMP_ALPHA;
			brush->collision = MOD_DPAINT_COL_VOLUME;
			
			brush->mat = NULL;
			brush->r = 0.15f;
			brush->g = 0.4f;
			brush->b = 0.8f;
			brush->alpha = 1.0f;
			brush->wetness = 1.0f;

			brush->paint_distance = 1.0f;
			brush->proximity_falloff = MOD_DPAINT_PRFALL_SMOOTH;

			brush->particle_radius = 0.2f;
			brush->particle_smooth = 0.05f;

			brush->wave_type = MOD_DPAINT_WAVEB_CHANGE;
			brush->wave_factor = 1.0f;
			brush->wave_clamp = 0.0f;
			brush->smudge_strength = 0.3f;
			brush->max_velocity = 1.0f;

			brush->dm = NULL;

			/* Paint proximity falloff colorramp. */
			{
				CBData *ramp;

				brush->paint_ramp = add_colorband(false);
				if (!brush->paint_ramp)
					return false;
				ramp = brush->paint_ramp->data;
				/* Add default smooth-falloff ramp.	*/
				ramp[0].r = ramp[0].g = ramp[0].b = ramp[0].a = 1.0f;
				ramp[0].pos = 0.0f;
				ramp[1].r = ramp[1].g = ramp[1].b = ramp[1].pos = 1.0f;
				ramp[1].a = 0.0f;
				pmd->brush->paint_ramp->tot = 2;
			}

			/* Brush velocity ramp. */
			{
				CBData *ramp;

				brush->vel_ramp = add_colorband(false);
				if (!brush->vel_ramp)
					return false;
				ramp = brush->vel_ramp->data;
				ramp[0].r = ramp[0].g = ramp[0].b = ramp[0].a = ramp[0].pos = 0.0f;
				ramp[1].r = ramp[1].g = ramp[1].b = ramp[1].a = ramp[1].pos = 1.0f;
				brush->paint_ramp->tot = 2;
			}
		}
	}
	else {
		return false;
	}

	return true;
}

void dynamicPaint_Modifier_copy(struct DynamicPaintModifierData *pmd, struct DynamicPaintModifierData *tpmd)
{
	/* Init modifier	*/
	tpmd->type = pmd->type;
	if (pmd->canvas)
		dynamicPaint_createType(tpmd, MOD_DYNAMICPAINT_TYPE_CANVAS, NULL);
	if (pmd->brush)
		dynamicPaint_createType(tpmd, MOD_DYNAMICPAINT_TYPE_BRUSH, NULL);

	/* Copy data	*/
	if (tpmd->canvas) {
		DynamicPaintSurface *surface;
		tpmd->canvas->pmd = tpmd;
		/* free default surface */
		if (tpmd->canvas->surfaces.first)
			dynamicPaint_freeSurface(tpmd->canvas->surfaces.first);

		/* copy existing surfaces */
		for (surface = pmd->canvas->surfaces.first; surface; surface = surface->next) {
			DynamicPaintSurface *t_surface = dynamicPaint_createNewSurface(tpmd->canvas, NULL);

			/* surface settings */
			t_surface->brush_group = surface->brush_group;
			MEM_freeN(t_surface->effector_weights);
			t_surface->effector_weights = MEM_dupallocN(surface->effector_weights);

			BLI_strncpy(t_surface->name, surface->name, sizeof(t_surface->name));
			t_surface->format = surface->format;
			t_surface->type = surface->type;
			t_surface->disp_type = surface->disp_type;
			t_surface->image_fileformat = surface->image_fileformat;
			t_surface->effect_ui = surface->effect_ui;
			t_surface->preview_id = surface->preview_id;
			t_surface->init_color_type = surface->init_color_type;
			t_surface->flags = surface->flags;
			t_surface->effect = surface->effect;

			t_surface->image_resolution = surface->image_resolution;
			t_surface->substeps = surface->substeps;
			t_surface->start_frame = surface->start_frame;
			t_surface->end_frame = surface->end_frame;

			copy_v4_v4(t_surface->init_color, surface->init_color);
			t_surface->init_texture = surface->init_texture;
			BLI_strncpy(t_surface->init_layername, surface->init_layername, sizeof(t_surface->init_layername));

			t_surface->dry_speed = surface->dry_speed;
			t_surface->diss_speed = surface->diss_speed;
			t_surface->color_dry_threshold = surface->color_dry_threshold;
			t_surface->depth_clamp = surface->depth_clamp;
			t_surface->disp_factor = surface->disp_factor;


			t_surface->spread_speed = surface->spread_speed;
			t_surface->color_spread_speed = surface->color_spread_speed;
			t_surface->shrink_speed = surface->shrink_speed;
			t_surface->drip_vel = surface->drip_vel;
			t_surface->drip_acc = surface->drip_acc;

			t_surface->influence_scale = surface->influence_scale;
			t_surface->radius_scale = surface->radius_scale;

			t_surface->wave_damping = surface->wave_damping;
			t_surface->wave_speed = surface->wave_speed;
			t_surface->wave_timescale = surface->wave_timescale;
			t_surface->wave_spring = surface->wave_spring;
			t_surface->wave_smoothness = surface->wave_smoothness;

			BLI_strncpy(t_surface->uvlayer_name, surface->uvlayer_name, sizeof(t_surface->uvlayer_name));
			BLI_strncpy(t_surface->image_output_path, surface->image_output_path, sizeof(t_surface->image_output_path));
			BLI_strncpy(t_surface->output_name, surface->output_name, sizeof(t_surface->output_name));
			BLI_strncpy(t_surface->output_name2, surface->output_name2, sizeof(t_surface->output_name2));
		}
		dynamicPaint_resetPreview(tpmd->canvas);
	}
	else if (tpmd->brush) {
		DynamicPaintBrushSettings *brush = pmd->brush, *t_brush = tpmd->brush;
		t_brush->pmd = tpmd;

		t_brush->flags = brush->flags;
		t_brush->collision = brush->collision;

		t_brush->mat = brush->mat;
		t_brush->r = brush->r;
		t_brush->g = brush->g;
		t_brush->b = brush->b;
		t_brush->alpha = brush->alpha;
		t_brush->wetness = brush->wetness;

		t_brush->particle_radius = brush->particle_radius;
		t_brush->particle_smooth = brush->particle_smooth;
		t_brush->paint_distance = brush->paint_distance;
		t_brush->psys = brush->psys;

		if (brush->paint_ramp)
			memcpy(t_brush->paint_ramp, brush->paint_ramp, sizeof(ColorBand));
		if (brush->vel_ramp)
			memcpy(t_brush->vel_ramp, brush->vel_ramp, sizeof(ColorBand));

		t_brush->proximity_falloff = brush->proximity_falloff;
		t_brush->wave_type = brush->wave_type;
		t_brush->ray_dir = brush->ray_dir;

		t_brush->wave_factor = brush->wave_factor;
		t_brush->wave_clamp = brush->wave_clamp;
		t_brush->max_velocity = brush->max_velocity;
		t_brush->smudge_strength = brush->smudge_strength;
	}
}

/* allocates surface data depending on surface type */
static void dynamicPaint_allocateSurfaceType(DynamicPaintSurface *surface)
{
	PaintSurfaceData *sData = surface->data;

	switch (surface->type) {
		case MOD_DPAINT_SURFACE_T_PAINT:
			sData->type_data = MEM_callocN(sizeof(PaintPoint) * sData->total_points, "DynamicPaintSurface Data");
			break;
		case MOD_DPAINT_SURFACE_T_DISPLACE:
			sData->type_data = MEM_callocN(sizeof(float) * sData->total_points, "DynamicPaintSurface DepthData");
			break;
		case MOD_DPAINT_SURFACE_T_WEIGHT:
			sData->type_data = MEM_callocN(sizeof(float) * sData->total_points, "DynamicPaintSurface WeightData");
			break;
		case MOD_DPAINT_SURFACE_T_WAVE:
			sData->type_data = MEM_callocN(sizeof(PaintWavePoint) * sData->total_points, "DynamicPaintSurface WaveData");
			break;
	}

	if (sData->type_data == NULL) setError(surface->canvas, N_("Not enough free memory"));
}

static int surface_usesAdjDistance(DynamicPaintSurface *surface)
{
	if (surface->type == MOD_DPAINT_SURFACE_T_PAINT && surface->effect) return 1;
	if (surface->type == MOD_DPAINT_SURFACE_T_WAVE) return 1;
	return 0;
}

static int surface_usesAdjData(DynamicPaintSurface *surface)
{
	if (surface_usesAdjDistance(surface)) return 1;
	if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX &&
	    surface->flags & MOD_DPAINT_ANTIALIAS)
	{
		return 1;
	}
	else {
		return 0;
	}
}

/* initialize surface adjacency data */
static void dynamicPaint_initAdjacencyData(DynamicPaintSurface *surface, int force_init)
{
	PaintSurfaceData *sData = surface->data;
	DerivedMesh *dm = surface->canvas->dm;
	PaintAdjData *ad;
	int *temp_data;
	int neigh_points = 0;

	if (!surface_usesAdjData(surface) && !force_init) return;

	if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
		/* For vertex format, neighbors are connected by edges */
		neigh_points = 2 * dm->getNumEdges(dm);
	}
	else if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ)
		neigh_points = sData->total_points * 8;

	if (!neigh_points) return;

	/* allocate memory */
	ad = sData->adj_data = MEM_callocN(sizeof(PaintAdjData), "Surface Adj Data");
	if (!ad) return;
	ad->n_index = MEM_callocN(sizeof(int) * sData->total_points, "Surface Adj Index");
	ad->n_num = MEM_callocN(sizeof(int) * sData->total_points, "Surface Adj Counts");
	temp_data = MEM_callocN(sizeof(int) * sData->total_points, "Temp Adj Data");
	ad->n_target = MEM_callocN(sizeof(int) * neigh_points, "Surface Adj Targets");
	ad->flags = MEM_callocN(sizeof(int) * sData->total_points, "Surface Adj Flags");
	ad->total_targets = neigh_points;

	/* in case of allocation error, free memory */
	if (!ad->n_index || !ad->n_num || !ad->n_target || !temp_data) {
		dynamicPaint_freeAdjData(sData);
		if (temp_data) MEM_freeN(temp_data);
		setError(surface->canvas, N_("Not enough free memory"));
		return;
	}

	if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
		int i;
		int n_pos;

		/* For vertex format, count every vertex that is connected by an edge */
		int numOfEdges = dm->getNumEdges(dm);
		int numOfPolys = dm->getNumPolys(dm);
		struct MEdge *edge =  dm->getEdgeArray(dm);
		struct MPoly *mpoly = dm->getPolyArray(dm);
		struct MLoop *mloop = dm->getLoopArray(dm);

		/* count number of edges per vertex */
		for (i = 0; i < numOfEdges; i++) {
			ad->n_num[edge[i].v1]++;
			ad->n_num[edge[i].v2]++;

			temp_data[edge[i].v1]++;
			temp_data[edge[i].v2]++;
		}

		/* also add number of vertices to temp_data
		 *  to locate points on "mesh edge" */
		for (i = 0; i < numOfPolys; i++) {
			int j = 0;
			for (; j < mpoly[i].totloop; j++) {
				temp_data[mloop[mpoly[i].loopstart + j].v]++;
			}
		}

		/* now check if total number of edges+faces for
		 *  each vertex is even, if not -> vertex is on mesh edge */
		for (i = 0; i < sData->total_points; i++) {
			if ((temp_data[i] % 2) ||
			    (temp_data[i] < 4))
			{
				ad->flags[i] |= ADJ_ON_MESH_EDGE;
			}

			/* reset temp data */ 
			temp_data[i] = 0;
		}

		/* order n_index array */
		n_pos = 0;
		for (i = 0; i < sData->total_points; i++) {
			ad->n_index[i] = n_pos;
			n_pos += ad->n_num[i];
		}

		/* and now add neighbor data using that info */
		for (i = 0; i < numOfEdges; i++) {
			/* first vertex */
			int index = edge[i].v1;
			n_pos = ad->n_index[index] + temp_data[index];
			ad->n_target[n_pos] = edge[i].v2;
			temp_data[index]++;

			/* second vertex */
			index = edge[i].v2;
			n_pos = ad->n_index[index] + temp_data[index];
			ad->n_target[n_pos] = edge[i].v1;
			temp_data[index]++;
		}
	}
	else if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
		/* for image sequences, only allocate memory.
		 *  bake initialization takes care of rest */
	}

	MEM_freeN(temp_data);
}

static void dynamicPaint_setInitialColor(const Scene *scene, DynamicPaintSurface *surface)
{
	PaintSurfaceData *sData = surface->data;
	PaintPoint *pPoint = (PaintPoint *)sData->type_data;
	DerivedMesh *dm = surface->canvas->dm;
	int i;
	const bool scene_color_manage = BKE_scene_check_color_management_enabled(scene);

	if (surface->type != MOD_DPAINT_SURFACE_T_PAINT)
		return;

	if (surface->init_color_type == MOD_DPAINT_INITIAL_NONE)
		return;
	/* Single color */
	else if (surface->init_color_type == MOD_DPAINT_INITIAL_COLOR) {
		/* apply color to every surface point */
#pragma omp parallel for schedule(static)
		for (i = 0; i < sData->total_points; i++) {
			copy_v4_v4(pPoint[i].color, surface->init_color);
		}
	}
	/* UV mapped texture */
	else if (surface->init_color_type == MOD_DPAINT_INITIAL_TEXTURE) {
		Tex *tex = surface->init_texture;

		const MLoop *mloop = dm->getLoopArray(dm);
		const MLoopTri *mlooptri = dm->getLoopTriArray(dm);
		const int tottri = dm->getNumLoopTri(dm);
		const MLoopUV *mloopuv = NULL;

		char uvname[MAX_CUSTOMDATA_LAYER_NAME];

		if (!tex) return;

		/* get uv map */
		CustomData_validate_layer_name(&dm->loopData, CD_MLOOPUV, surface->init_layername, uvname);
		mloopuv = CustomData_get_layer_named(&dm->loopData, CD_MLOOPUV, uvname);
		if (!mloopuv) return;

		/* for vertex surface loop through tfaces and find uv color
		 *  that provides highest alpha */
		if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
			struct ImagePool *pool = BKE_image_pool_new();

#pragma omp parallel for schedule(static) shared(pool)
			for (i = 0; i < tottri; i++) {
				float uv[3] = {0.0f};
				int j;
				for (j = 0; j < 3; j++) {
					TexResult texres = {0};
					unsigned int vert = mloop[mlooptri[i].tri[j]].v;

					/* remap to -1.0 to 1.0 */
					uv[0] = mloopuv[mlooptri[i].tri[j]].uv[0] * 2.0f - 1.0f;
					uv[1] = mloopuv[mlooptri[i].tri[j]].uv[1] * 2.0f - 1.0f;

					multitex_ext_safe(tex, uv, &texres, pool, scene_color_manage, false);

					if (texres.tin > pPoint[vert].color[3]) {
						copy_v3_v3(pPoint[vert].color, &texres.tr);
						pPoint[vert].color[3] = texres.tin;
					}
				}
			}
			BKE_image_pool_free(pool);
		}
		else if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
			ImgSeqFormatData *f_data = (ImgSeqFormatData *)sData->format_data;
			int samples = (surface->flags & MOD_DPAINT_ANTIALIAS) ? 5 : 1;

#pragma omp parallel for schedule(static)
			for (i = 0; i < sData->total_points; i++) {
				float uv[9] = {0.0f};
				float uv_final[3] = {0.0f};
				int j;
				TexResult texres = {0};

				/* collect all uvs */
				for (j = 0; j < 3; j++) {
					copy_v2_v2(&uv[j * 3], mloopuv[mlooptri[f_data->uv_p[i].tri_index].tri[j]].uv);
				}

				/* interpolate final uv pos */
				interp_v3_v3v3v3(uv_final, &uv[0], &uv[3], &uv[6],
				                 f_data->barycentricWeights[i * samples].v);
				/* remap to -1.0 to 1.0 */
				uv_final[0] = uv_final[0] * 2.0f - 1.0f;
				uv_final[1] = uv_final[1] * 2.0f - 1.0f;

				multitex_ext_safe(tex, uv_final, &texres, NULL, scene_color_manage, false);

				/* apply color */
				copy_v3_v3(pPoint[i].color, &texres.tr);
				pPoint[i].color[3] = texres.tin;
			}
		}
	}
	/* vertex color layer */
	else if (surface->init_color_type == MOD_DPAINT_INITIAL_VERTEXCOLOR) {

		/* for vertex surface, just copy colors from mcol */
		if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
			const MLoop *mloop = dm->getLoopArray(dm);
			const int totloop = dm->getNumLoops(dm);
			const MLoopCol *col = CustomData_get_layer_named(&dm->loopData, CD_MLOOPCOL, surface->init_layername);
			if (!col) return;

#pragma omp parallel for schedule(static)
			for (i = 0; i < totloop; i++) {
				rgba_uchar_to_float(pPoint[mloop[i].v].color, (const unsigned char *)&col[mloop[i].v].r);
			}
		}
		else if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
			const MLoopTri *mlooptri = dm->getLoopTriArray(dm);
			ImgSeqFormatData *f_data = (ImgSeqFormatData *)sData->format_data;
			int samples = (surface->flags & MOD_DPAINT_ANTIALIAS) ? 5 : 1;
			MLoopCol *col = CustomData_get_layer_named(&dm->loopData, CD_MLOOPCOL, surface->init_layername);
			if (!col) return;

#pragma omp parallel for schedule(static)
			for (i = 0; i < sData->total_points; i++) {
				int tri_ind = f_data->uv_p[i].tri_index;
				float colors[3][4];
				float final_color[4];
				int j;

				/* collect color values */
				for (j = 0; j < 3; j++) {
					rgba_uchar_to_float(colors[j], (const unsigned char *)&col[mlooptri[tri_ind].tri[j]].r);
				}

				/* interpolate final color */
				interp_v4_v4v4v4(final_color, UNPACK3(colors), f_data->barycentricWeights[i * samples].v);

				copy_v4_v4(pPoint[i].color, final_color);
			}
		}
	}
}

/* clears surface data back to zero */
void dynamicPaint_clearSurface(const Scene *scene, DynamicPaintSurface *surface)
{
	PaintSurfaceData *sData = surface->data;
	if (sData && sData->type_data) {
		unsigned int data_size;

		if (surface->type == MOD_DPAINT_SURFACE_T_PAINT)
			data_size = sizeof(PaintPoint);
		else if (surface->type == MOD_DPAINT_SURFACE_T_WAVE)
			data_size = sizeof(PaintWavePoint);
		else
			data_size = sizeof(float);

		memset(sData->type_data, 0, data_size * sData->total_points);

		/* set initial color */
		if (surface->type == MOD_DPAINT_SURFACE_T_PAINT)
			dynamicPaint_setInitialColor(scene, surface);

		if (sData->bData)
			sData->bData->clear = 1;
	}
}

/* completely (re)initializes surface (only for point cache types)*/
bool dynamicPaint_resetSurface(const Scene *scene, DynamicPaintSurface *surface)
{
	int numOfPoints = dynamicPaint_surfaceNumOfPoints(surface);
	/* free existing data */
	if (surface->data) dynamicPaint_freeSurfaceData(surface);

	/* don't reallocate for image sequence types. they get handled only on bake */
	if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) return true;
	if (numOfPoints < 1) return false;

	/* allocate memory */
	surface->data = MEM_callocN(sizeof(PaintSurfaceData), "PaintSurfaceData");
	if (!surface->data) return false;

	/* allocate data depending on surface type and format */
	surface->data->total_points = numOfPoints;
	dynamicPaint_allocateSurfaceType(surface);
	dynamicPaint_initAdjacencyData(surface, 0);

	/* set initial color */
	if (surface->type == MOD_DPAINT_SURFACE_T_PAINT)
		dynamicPaint_setInitialColor(scene, surface);

	return true;
}

/* make sure allocated surface size matches current requirements */
static bool dynamicPaint_checkSurfaceData(const Scene *scene, DynamicPaintSurface *surface)
{
	if (!surface->data || ((dynamicPaint_surfaceNumOfPoints(surface) != surface->data->total_points))) {
		return dynamicPaint_resetSurface(scene, surface);
	}
	return true;
}


/***************************** Modifier processing ******************************/


/* apply displacing vertex surface to the derived mesh */
static void dynamicPaint_applySurfaceDisplace(DynamicPaintSurface *surface, DerivedMesh *result)
{
	PaintSurfaceData *sData = surface->data;

	if (!sData || surface->format != MOD_DPAINT_SURFACE_F_VERTEX) return;

	/* displace paint */
	if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE) {
		MVert *mvert = result->getVertArray(result);
		int i;
		const float *value = (float *)sData->type_data;

#pragma omp parallel for schedule(static)
		for (i = 0; i < sData->total_points; i++) {
			float normal[3], val = value[i] * surface->disp_factor;
			normal_short_to_float_v3(normal, mvert[i].no);
			normalize_v3(normal);

			mvert[i].co[0] -= normal[0] * val;
			mvert[i].co[1] -= normal[1] * val;
			mvert[i].co[2] -= normal[2] * val;
		}
	}
}

/*
 *	Apply canvas data to the object derived mesh
 */
static DerivedMesh *dynamicPaint_Modifier_apply(DynamicPaintModifierData *pmd,
                                                Object *ob,
                                                DerivedMesh *dm)
{
	DerivedMesh *result = CDDM_copy(dm);

	if (pmd->canvas && !(pmd->canvas->flags & MOD_DPAINT_BAKING)) {

		DynamicPaintSurface *surface;
		bool update_normals = false;

		/* loop through surfaces */
		for (surface = pmd->canvas->surfaces.first; surface; surface = surface->next) {
			PaintSurfaceData *sData = surface->data;

			if (surface->format != MOD_DPAINT_SURFACE_F_IMAGESEQ && sData) {
				if (!(surface->flags & (MOD_DPAINT_ACTIVE))) continue;

				/* process vertex surface previews */
				if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {

					/* vertex color paint */
					if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {

						int i;
						PaintPoint *pPoint = (PaintPoint *)sData->type_data;
						MLoopCol *col = NULL;
						MLoop *mloop = CDDM_get_loops(result);
						int totloop = result->numLoopData;

						/* paint is stored on dry and wet layers, so mix final color first */
						float *fcolor = MEM_callocN(sizeof(float) * sData->total_points * 4, "Temp paint color");

#pragma omp parallel for schedule(static)
						for (i = 0; i < sData->total_points; i++) {
							/* blend dry and wet layer */
							blendColors(pPoint[i].color, pPoint[i].color[3], pPoint[i].e_color, pPoint[i].e_color[3], &fcolor[i * 4]);
						}

						/* viewport preview */
						if (surface->flags & MOD_DPAINT_PREVIEW) {
							MPoly *mp = CDDM_get_polys(result);
							int totpoly = result->numPolyData;

#if 0
							/* XXX We have to create a CD_PREVIEW_MCOL, else it might sigsev
							 *     (after a SubSurf mod, eg)... */
							if (!result->getTessFaceDataArray(result, CD_PREVIEW_MCOL)) {
								int numFaces = result->getNumTessFaces(result);
								CustomData_add_layer(&result->faceData, CD_PREVIEW_MCOL, CD_CALLOC, NULL, numFaces);
							}
#endif

							/* Save preview results to weight layer to be
							 *   able to share same drawing methods */
							col = CustomData_get_layer(&result->loopData, CD_PREVIEW_MLOOPCOL);
							if (!col)
								col = CustomData_add_layer(&result->loopData, CD_PREVIEW_MLOOPCOL, CD_CALLOC,
								                           NULL, totloop);

							if (col) {
#pragma omp parallel for schedule(static)
								for (i = 0; i < totpoly; i++) {
									int j = 0;
									Material *material = give_current_material(ob, mp[i].mat_nr + 1);

									for (; j < mp[i].totloop; j++) {
										int l_index = mp[i].loopstart + j;
										int v_index = mloop[l_index].v;

										if (surface->preview_id == MOD_DPAINT_SURFACE_PREV_PAINT) {
											float c[3];
											v_index *= 4;

											/* Apply material color as base vertex color for preview */
											col[l_index].a = 255;
											if (material) {
												c[0] = material->r;
												c[1] = material->g;
												c[2] = material->b;
											}
											else { /* default gray */
												c[0] = 0.65f;
												c[1] = 0.65f;
												c[2] = 0.65f;
											}
											/* mix surface color */
											interp_v3_v3v3(c, c, &fcolor[v_index], fcolor[v_index + 3]);

											rgb_float_to_uchar((unsigned char *)&col[l_index].r, c);
										}
										else {
											col[l_index].r =
											    col[l_index].g =
											        col[l_index].b = FTOCHAR(pPoint[v_index].wetness);
											col[l_index].a = 255;
										}
									}
								}
							}
						}


						/* save layer data to output layer */

						/* paint layer */
						col = CustomData_get_layer_named(&result->loopData, CD_MLOOPCOL, surface->output_name);
						/* if output layer is lost from a constructive modifier, re-add it */
						if (!col && dynamicPaint_outputLayerExists(surface, ob, 0))
							col = CustomData_add_layer_named(&result->loopData, CD_MLOOPCOL, CD_CALLOC, NULL, totloop, surface->output_name);
						/* apply color */
						if (col) {
#pragma omp parallel for schedule(static)
							for (i = 0; i < totloop; i++) {
								int index = mloop[i].v * 4;
								rgb_float_to_uchar((unsigned char *)&col[i].r, &fcolor[index]);
								col[i].a = FTOCHAR(fcolor[index + 3]); /* IS THIS NEEDED? */
							}
						}
						
						MEM_freeN(fcolor);

						/* wet layer */
						col = CustomData_get_layer_named(&result->loopData, CD_MLOOPCOL, surface->output_name2);
						/* if output layer is lost from a constructive modifier, re-add it */
						if (!col && dynamicPaint_outputLayerExists(surface, ob, 1))
							col = CustomData_add_layer_named(&result->loopData, CD_MLOOPCOL, CD_CALLOC, NULL, totloop, surface->output_name2);
						/* apply color */
						if (col) {
#pragma omp parallel for schedule(static)
							for (i = 0; i < totloop; i++) {
								int index = mloop[i].v;
								col[i].r =
								    col[i].g =
								        col[i].b = FTOCHAR(pPoint[index].wetness);
								col[i].a = 255;
							}
						}

						/* Mark tessellated CD layers as dirty. */
						result->dirty |= DM_DIRTY_TESS_CDLAYERS;
					}
					/* vertex group paint */
					else if (surface->type == MOD_DPAINT_SURFACE_T_WEIGHT) {
						int defgrp_index = defgroup_name_index(ob, surface->output_name);
						MDeformVert *dvert = result->getVertDataArray(result, CD_MDEFORMVERT);
						float *weight = (float *)sData->type_data;

						/* viewport preview */
						if (surface->flags & MOD_DPAINT_PREVIEW) {
							/* Save preview results to weight layer to be
							 * able to share same drawing methods.
							 * Note this func also sets DM_DIRTY_TESS_CDLAYERS flag! */
							DM_update_weight_mcol(ob, result, 0, weight, 0, NULL);
						}

						/* apply weights into a vertex group, if doesnt exists add a new layer */
						if (defgrp_index != -1 && !dvert && (surface->output_name[0] != '\0'))
							dvert = CustomData_add_layer_named(&result->vertData, CD_MDEFORMVERT, CD_CALLOC,
							                                   NULL, sData->total_points, surface->output_name);
						if (defgrp_index != -1 && dvert) {
							int i;
							for (i = 0; i < sData->total_points; i++) {
								MDeformVert *dv = &dvert[i];
								MDeformWeight *def_weight = defvert_find_index(dv, defgrp_index);

								/* skip if weight value is 0 and no existing weight is found */
								if ((def_weight != NULL) || (weight[i] != 0.0f)) {

									/* if not found, add a weight for it */
									if (def_weight == NULL) {
										def_weight = defvert_verify_index(dv, defgrp_index);
									}

									/* set weight value */
									def_weight->weight = weight[i];
								}
							}
						}
					}
					/* wave simulation */
					else if (surface->type == MOD_DPAINT_SURFACE_T_WAVE) {
						MVert *mvert = result->getVertArray(result);
						int i;
						PaintWavePoint *wPoint = (PaintWavePoint *)sData->type_data;

#pragma omp parallel for schedule(static)
						for (i = 0; i < sData->total_points; i++) {
							float normal[3];
							normal_short_to_float_v3(normal, mvert[i].no);
							madd_v3_v3fl(mvert[i].co, normal, wPoint[i].height);
						}
						update_normals = true;
					}

					/* displace */
					if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE) {
						dynamicPaint_applySurfaceDisplace(surface, result);
						update_normals = true;
					}
				}
			}
		}

		if (update_normals) {
			result->dirty |= DM_DIRTY_NORMALS;
		}
	}
	/* make a copy of dm to use as brush data */
	if (pmd->brush) {
		if (pmd->brush->dm) pmd->brush->dm->release(pmd->brush->dm);
		pmd->brush->dm = CDDM_copy(result);
	}

	return result;
}

/* update cache frame range */
void dynamicPaint_cacheUpdateFrames(DynamicPaintSurface *surface)
{
	if (surface->pointcache) {
		surface->pointcache->startframe = surface->start_frame;
		surface->pointcache->endframe = surface->end_frame;
	}
}

static void canvas_copyDerivedMesh(DynamicPaintCanvasSettings *canvas, DerivedMesh *dm)
{
	if (canvas->dm) {
		canvas->dm->release(canvas->dm);
	}

	canvas->dm = CDDM_copy(dm);
}

/*
 *	Updates derived mesh copy and processes dynamic paint step / caches.
 */
static void dynamicPaint_frameUpdate(DynamicPaintModifierData *pmd, Scene *scene, Object *ob, DerivedMesh *dm)
{
	if (pmd->canvas) {
		DynamicPaintCanvasSettings *canvas = pmd->canvas;
		DynamicPaintSurface *surface = canvas->surfaces.first;

		/* update derived mesh copy */
		canvas_copyDerivedMesh(canvas, dm);

		/* in case image sequence baking, stop here */
		if (canvas->flags & MOD_DPAINT_BAKING) return;

		/* loop through surfaces */
		for (; surface; surface = surface->next) {
			int current_frame = (int)scene->r.cfra;
			bool no_surface_data;

			/* free bake data if not required anymore */
			surface_freeUnusedData(surface);

			/* image sequences are handled by bake operator */
			if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) continue;
			if (!(surface->flags & MOD_DPAINT_ACTIVE)) continue;

			/* make sure surface is valid */
			no_surface_data = surface->data == NULL;
			if (!dynamicPaint_checkSurfaceData(scene, surface)) continue;

			/* limit frame range */
			CLAMP(current_frame, surface->start_frame, surface->end_frame);

			if (no_surface_data || current_frame != surface->current_frame || (int)scene->r.cfra == surface->start_frame) {
				PointCache *cache = surface->pointcache;
				PTCacheID pid;
				surface->current_frame = current_frame;

				/* read point cache */
				BKE_ptcache_id_from_dynamicpaint(&pid, ob, surface);
				pid.cache->startframe = surface->start_frame;
				pid.cache->endframe = surface->end_frame;
				BKE_ptcache_id_time(&pid, scene, (float)scene->r.cfra, NULL, NULL, NULL);

				/* reset non-baked cache at first frame */
				if ((int)scene->r.cfra == surface->start_frame && !(cache->flag & PTCACHE_BAKED)) {
					cache->flag |= PTCACHE_REDO_NEEDED;
					BKE_ptcache_id_reset(scene, &pid, PTCACHE_RESET_OUTDATED);
					cache->flag &= ~PTCACHE_REDO_NEEDED;
				}

				/* try to read from cache */
				if (BKE_ptcache_read(&pid, (float)scene->r.cfra)) {
					BKE_ptcache_validate(cache, (int)scene->r.cfra);
				}
				/* if read failed and we're on surface range do recalculate */
				else if ((int)scene->r.cfra == current_frame && !(cache->flag & PTCACHE_BAKED)) {
					/* calculate surface frame */
					canvas->flags |= MOD_DPAINT_BAKING;
					dynamicPaint_calculateFrame(surface, scene, ob, current_frame);
					canvas->flags &= ~MOD_DPAINT_BAKING;

					/* restore canvas derivedmesh if required */
					if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE &&
					    surface->flags & MOD_DPAINT_DISP_INCREMENTAL && surface->next)
					{
						canvas_copyDerivedMesh(canvas, dm);
					}

					BKE_ptcache_validate(cache, surface->current_frame);
					BKE_ptcache_write(&pid, surface->current_frame);
				}
			}
		}
	}
}

/* Modifier call. Processes dynamic paint modifier step. */
DerivedMesh *dynamicPaint_Modifier_do(DynamicPaintModifierData *pmd, Scene *scene, Object *ob, DerivedMesh *dm)
{
	/* For now generate looptris in every case */
	DM_ensure_looptri(dm);

	/* Update canvas data for a new frame */
	dynamicPaint_frameUpdate(pmd, scene, ob, dm);

	/* Return output mesh */
	return dynamicPaint_Modifier_apply(pmd, ob, dm);
}


/***************************** Image Sequence / UV Image Surface Calls ******************************/

/*
 *	Tries to find the neighboring pixel in given (uv space) direction.
 *	Result is used by effect system to move paint on the surface.
 *
 *   px, py : origin pixel x and y
 *	n_index : lookup direction index (use neighX, neighY to get final index)
 */
static int dynamicPaint_findNeighbourPixel(PaintUVPoint *tempPoints, DerivedMesh *dm,
                                           const char *uvname, int w, int h, int px, int py, int n_index)
{
	/* Note: Current method only uses polygon edges to detect neighboring pixels.
	 *  -> It doesn't always lead to the optimum pixel but is accurate enough
	 *  and faster/simpler than including possible face tip point links)
	 */

	int x, y;
	PaintUVPoint *tPoint = NULL;
	PaintUVPoint *cPoint = NULL;

	/* shift position by given n_index */
	x = px + neighX[n_index];
	y = py + neighY[n_index];

	if (x < 0 || x >= w) return OUT_OF_TEXTURE;
	if (y < 0 || y >= h) return OUT_OF_TEXTURE;

	tPoint = &tempPoints[x + w * y];        /* UV neighbor */
	cPoint = &tempPoints[px + w * py];      /* Origin point */

	/*
	 *	Check if shifted point is on same face -> it's a correct neighbor
	 *   (and if it isn't marked as an "edge pixel")
	 */
	if ((tPoint->tri_index == cPoint->tri_index) && (tPoint->neighbour_pixel == -1))
		return (x + w * y);

	/*
	 *	Even if shifted point is on another face
	 *	-> use this point.
	 *
	 *	!! Replace with "is uv faces linked" check !!
	 *	This should work fine as long as uv island
	 *	margin is > 1 pixel.
	 */
	if ((tPoint->tri_index != -1) && (tPoint->neighbour_pixel == -1)) {
		return (x + w * y);
	}

	/*
	 *	If we get here, the actual neighboring pixel
	 *	is located on a non-linked uv face, and we have to find
	 *	it's "real" position.
	 *
	 *	Simple neighboring face finding algorithm:
	 *	- find closest uv edge to shifted pixel and get
	 *	  the another face that shares that edge
	 *	- find corresponding position of that new face edge
	 *	  in uv space
	 *
	 *	TODO: Implement something more accurate / optimized?
	 */
	{
		const MLoop *mloop = dm->getLoopArray(dm);
		const MLoopTri *mlooptri = dm->getLoopTriArray(dm);
		const int tottri = dm->getNumLoopTri(dm);
		const MLoopUV *mloopuv = CustomData_get_layer_named(&dm->loopData, CD_MLOOPUV, uvname);

		/* Get closest edge to that subpixel on UV map	*/
		{
			float pixel[2];
			/* distances only used for comparison */
			float dist_squared, t_dist_squared;

			int i, edge1_index, edge2_index,
			    e1_index, e2_index, target_tri;
			float closest_point[2], lambda, dir_vec[2];
			int target_uv1 = 0, target_uv2 = 0, final_pixel[2], final_index;

			const float *s_uv1, *s_uv2, *t_uv1, *t_uv2;

			pixel[0] = ((float)(px + neighX[n_index]) + 0.5f) / (float)w;
			pixel[1] = ((float)(py + neighY[n_index]) + 0.5f) / (float)h;

			/*
			 *	Find closest edge to that pixel
			 */

			/* Dist to first edge */
			e1_index = cPoint->v1;
			e2_index = cPoint->v2;
			edge1_index = 0;
			edge2_index = 1;
			dist_squared = dist_squared_to_line_segment_v2(
			        pixel,
			        mloopuv[mlooptri[cPoint->tri_index].tri[0]].uv,
			        mloopuv[mlooptri[cPoint->tri_index].tri[1]].uv);

			/* Dist to second edge */
			t_dist_squared = dist_squared_to_line_segment_v2(
			        pixel,
			        mloopuv[mlooptri[cPoint->tri_index].tri[1]].uv,
			        mloopuv[mlooptri[cPoint->tri_index].tri[2]].uv);
			if (t_dist_squared < dist_squared) {
				e1_index = cPoint->v2;
				e2_index = cPoint->v3;
				edge1_index = 1;
				edge2_index = 2;
				dist_squared = t_dist_squared;
			}

			/* Dist to third edge */
			t_dist_squared = dist_squared_to_line_segment_v2(
			        pixel,
			        mloopuv[mlooptri[cPoint->tri_index].tri[2]].uv,
			        mloopuv[mlooptri[cPoint->tri_index].tri[0]].uv);
			if (t_dist_squared < dist_squared) {
				e1_index = cPoint->v3;
				e2_index = cPoint->v1;
				edge1_index = 2;
				edge2_index = 0;
				dist_squared = t_dist_squared;
			}


			/*
			 *	Now find another face that is linked to that edge
			 */
			target_tri = -1;

			for (i = 0; i < tottri; i++) {
				/*
				 *	Check if both edge vertices share this face
				 */
				if ((e1_index == mloop[mlooptri[i].tri[0]].v || e1_index == mloop[mlooptri[i].tri[1]].v || e1_index == mloop[mlooptri[i].tri[2]].v) &&
				    (e2_index == mloop[mlooptri[i].tri[0]].v || e2_index == mloop[mlooptri[i].tri[1]].v || e2_index == mloop[mlooptri[i].tri[2]].v))
				{
					if (i == cPoint->tri_index) continue;

					target_tri = i;

					/*
					 *	Get edge UV index
					 */
					if      (e1_index == mloop[mlooptri[i].tri[0]].v) target_uv1 = 0;
					else if (e1_index == mloop[mlooptri[i].tri[1]].v) target_uv1 = 1;
					else if (e1_index == mloop[mlooptri[i].tri[2]].v) target_uv1 = 2;

					if      (e2_index == mloop[mlooptri[i].tri[0]].v) target_uv2 = 0;
					else if (e2_index == mloop[mlooptri[i].tri[1]].v) target_uv2 = 1;
					else if (e2_index == mloop[mlooptri[i].tri[2]].v) target_uv2 = 2;

					break;
				}
			}

			/* If none found pixel is on mesh edge	*/
			if (target_tri == -1) return ON_MESH_EDGE;

			/*
			 *	If target face is connected in UV space as well, just use original index
			 */
			s_uv1 = mloopuv[mlooptri[cPoint->tri_index].tri[edge1_index]].uv;
			s_uv2 = mloopuv[mlooptri[cPoint->tri_index].tri[edge2_index]].uv;
			t_uv1 = mloopuv[mlooptri[target_tri].tri[target_uv1]].uv;
			t_uv2 = mloopuv[mlooptri[target_tri].tri[target_uv2]].uv;

			//printf("connected UV : %f,%f & %f,%f - %f,%f & %f,%f\n", s_uv1[0], s_uv1[1], s_uv2[0], s_uv2[1], t_uv1[0], t_uv1[1], t_uv2[0], t_uv2[1]);

			if (((s_uv1[0] == t_uv1[0] && s_uv1[1] == t_uv1[1]) &&
			     (s_uv2[0] == t_uv2[0] && s_uv2[1] == t_uv2[1]) ) ||
			    ((s_uv2[0] == t_uv1[0] && s_uv2[1] == t_uv1[1]) &&
			     (s_uv1[0] == t_uv2[0] && s_uv1[1] == t_uv2[1]) ))
			{
				return ((px + neighX[n_index]) + w * (py + neighY[n_index]));
			}

			/*
			 *	Find a point that is relatively at same edge position
			 *	on this other face UV
			 */
			lambda = closest_to_line_v2(
			        closest_point, pixel,
			        mloopuv[mlooptri[cPoint->tri_index].tri[edge1_index]].uv,
			        mloopuv[mlooptri[cPoint->tri_index].tri[edge2_index]].uv);
			if (lambda < 0.0f) lambda = 0.0f;
			if (lambda > 1.0f) lambda = 1.0f;

			sub_v2_v2v2(
			        dir_vec,
			        mloopuv[mlooptri[target_tri].tri[target_uv2]].uv,
			        mloopuv[mlooptri[target_tri].tri[target_uv1]].uv);

			mul_v2_fl(dir_vec, lambda);

			copy_v2_v2(pixel, mloopuv[mlooptri[target_tri].tri[target_uv1]].uv);
			add_v2_v2(pixel, dir_vec);
			pixel[0] = (pixel[0] * (float)w) - 0.5f;
			pixel[1] = (pixel[1] * (float)h) - 0.5f;

			final_pixel[0] = (int)floor(pixel[0]);
			final_pixel[1] = (int)floor(pixel[1]);

			/* If current pixel uv is outside of texture	*/
			if (final_pixel[0] < 0 || final_pixel[0] >= w) return OUT_OF_TEXTURE;
			if (final_pixel[1] < 0 || final_pixel[1] >= h) return OUT_OF_TEXTURE;

			final_index = final_pixel[0] + w * final_pixel[1];

			/* If we ended up to our origin point ( mesh has smaller than pixel sized faces)	*/
			if (final_index == (px + w * py)) return NOT_FOUND;
			/* If found pixel still lies on wrong face ( mesh has smaller than pixel sized faces)	*/
			if (tempPoints[final_index].tri_index != target_tri) {
				return NOT_FOUND;
			}

			/*
			 *	If final point is an "edge pixel", use it's "real" neighbor instead
			 */
			if (tempPoints[final_index].neighbour_pixel != -1) final_index = cPoint->neighbour_pixel;

			return final_index;
		}
	}
}

/*
 *	Create a surface for uv image sequence format
 */
int dynamicPaint_createUVSurface(Scene *scene, DynamicPaintSurface *surface)
{
	/* Antialias jitter point relative coords	*/
	const float jitter5sample[10] =  {
		    0.0f, 0.0f,
		    -0.2f, -0.4f,
		    0.2f, 0.4f,
		    0.4f, -0.2f,
		    -0.4f, 0.3f,
	};
	int ty;
	int w, h;
	int tottri;
	char uvname[MAX_CUSTOMDATA_LAYER_NAME];
	int active_points = 0;
	int error = 0;

	PaintSurfaceData *sData;
	DynamicPaintCanvasSettings *canvas = surface->canvas;
	DerivedMesh *dm = canvas->dm;

	PaintUVPoint *tempPoints = NULL;
	Vec3f *tempWeights = NULL;
	const MLoopTri *mlooptri = NULL;
	const MLoopUV *mloopuv = NULL;
	const MLoop *mloop = NULL;

	Bounds2D *faceBB = NULL;
	int *final_index;
	int aa_samples;

	if (!dm)
		return setError(canvas, N_("Canvas mesh not updated"));
	if (surface->format != MOD_DPAINT_SURFACE_F_IMAGESEQ)
		return setError(canvas, N_("Cannot bake non-'image sequence' formats"));

	mloop = dm->getLoopArray(dm);
	mlooptri = dm->getLoopTriArray(dm);
	tottri = dm->getNumLoopTri(dm);

	/* get uv map */
	CustomData_validate_layer_name(&dm->loopData, CD_MLOOPUV, surface->uvlayer_name, uvname);
	mloopuv = CustomData_get_layer_named(&dm->loopData, CD_MLOOPUV, uvname);

	/* Check for validity	*/
	if (!mloopuv)
		return setError(canvas, N_("No UV data on canvas"));
	if (surface->image_resolution < 16 || surface->image_resolution > 8192)
		return setError(canvas, N_("Invalid resolution"));

	w = h = surface->image_resolution;

	/*
	 *	Start generating the surface
	 */
	printf("DynamicPaint: Preparing UV surface of %ix%i pixels and %i tris.\n", w, h, tottri);

	/* Init data struct */
	if (surface->data) dynamicPaint_freeSurfaceData(surface);
	sData = surface->data = MEM_callocN(sizeof(PaintSurfaceData), "PaintSurfaceData");
	if (!surface->data)
		return setError(canvas, N_("Not enough free memory"));

	aa_samples = (surface->flags & MOD_DPAINT_ANTIALIAS) ? 5 : 1;
	tempPoints = (struct PaintUVPoint *) MEM_callocN(w * h * sizeof(struct PaintUVPoint), "Temp PaintUVPoint");
	if (!tempPoints) error = 1;

	final_index = (int *) MEM_callocN(w * h * sizeof(int), "Temp UV Final Indexes");
	if (!final_index) error = 1;

	tempWeights = (struct Vec3f *) MEM_mallocN(w * h * aa_samples * sizeof(struct Vec3f), "Temp bWeights");
	if (!tempWeights) error = 1;

	/*
	 *	Generate a temporary bounding box array for UV faces to optimize
	 *	the pixel-inside-a-face search.
	 */
	if (!error) {
		faceBB = (struct Bounds2D *) MEM_mallocN(tottri * sizeof(struct Bounds2D), "MPCanvasFaceBB");
		if (!faceBB) error = 1;
	}

	if (!error)
		for (ty = 0; ty < tottri; ty++) {
			int i;

			copy_v2_v2(faceBB[ty].min, mloopuv[mlooptri[ty].tri[0]].uv);
			copy_v2_v2(faceBB[ty].max, mloopuv[mlooptri[ty].tri[0]].uv);

			for (i = 1; i < 3; i++) {
				CLAMP_MAX(faceBB[ty].min[0], mloopuv[mlooptri[ty].tri[i]].uv[0]);
				CLAMP_MAX(faceBB[ty].min[1], mloopuv[mlooptri[ty].tri[i]].uv[1]);
				CLAMP_MIN(faceBB[ty].max[0], mloopuv[mlooptri[ty].tri[i]].uv[0]);
				CLAMP_MIN(faceBB[ty].max[1], mloopuv[mlooptri[ty].tri[i]].uv[1]);
			}
		}

	/*
	 *	Loop through every pixel and check
	 *	if pixel is uv-mapped on a canvas face.
	 */
	if (!error) {
#pragma omp parallel for schedule(static)
		for (ty = 0; ty < h; ty++) {
			int tx;
			for (tx = 0; tx < w; tx++) {
				int i, sample;
				int index = tx + w * ty;
				PaintUVPoint *tPoint = (&tempPoints[index]);

				bool isInside = false; /* if point is inside a uv face */

				float d1[2], d2[2], d3[2], point[5][2];
				float dot00, dot01, dot02, dot11, dot12, invDenom, u, v;

				/* Init per pixel settings */
				tPoint->tri_index = -1;
				tPoint->neighbour_pixel = -1;
				tPoint->pixel_index = index;

				/* Actual pixel center, used when collision is found	*/
				point[0][0] = ((float)tx + 0.5f) / w;
				point[0][1] = ((float)ty + 0.5f) / h;

				/*
				 * A pixel middle sample isn't enough to find very narrow polygons
				 * So using 4 samples of each corner too
				 */
				point[1][0] = ((float)tx) / w;
				point[1][1] = ((float)ty) / h;

				point[2][0] = ((float)tx + 1) / w;
				point[2][1] = ((float)ty) / h;

				point[3][0] = ((float)tx) / w;
				point[3][1] = ((float)ty + 1) / h;

				point[4][0] = ((float)tx + 1) / w;
				point[4][1] = ((float)ty + 1) / h;


				/* Loop through samples, starting from middle point	*/
				for (sample = 0; sample < 5; sample++) {

					/* Loop through every face in the mesh	*/
					for (i = 0; i < tottri; i++) {

						/* Check uv bb	*/
						if (faceBB[i].min[0] > (point[sample][0])) continue;
						if (faceBB[i].min[1] > (point[sample][1])) continue;
						if (faceBB[i].max[0] < (point[sample][0])) continue;
						if (faceBB[i].max[1] < (point[sample][1])) continue;

						/*  Calculate point inside a triangle check
						 *	for uv0, 1, 2 */
						sub_v2_v2v2(d1,  mloopuv[mlooptri[i].tri[2]].uv, mloopuv[mlooptri[i].tri[0]].uv);   /* uv2 - uv0 */
						sub_v2_v2v2(d2,  mloopuv[mlooptri[i].tri[1]].uv, mloopuv[mlooptri[i].tri[0]].uv);   /* uv1 - uv0 */
						sub_v2_v2v2(d3,  point[sample], mloopuv[mlooptri[i].tri[0]].uv);                    /* point - uv0 */

						dot00 = d1[0] * d1[0] + d1[1] * d1[1];
						dot01 = d1[0] * d2[0] + d1[1] * d2[1];
						dot02 = d1[0] * d3[0] + d1[1] * d3[1];
						dot11 = d2[0] * d2[0] + d2[1] * d2[1];
						dot12 = d2[0] * d3[0] + d2[1] * d3[1];

						invDenom = (dot00 * dot11 - dot01 * dot01);
						invDenom = invDenom ? 1.0f / invDenom : 1.0f;
						u = (dot11 * dot02 - dot01 * dot12) * invDenom;
						v = (dot00 * dot12 - dot01 * dot02) * invDenom;

						if ((u > 0) && (v > 0) && (u + v < 1)) { isInside = true; } /* is inside a triangle */

						/*
						 *	If point was inside the face
						 */
						if (isInside) {

							float uv1co[2], uv2co[2], uv3co[2], uv[2];
							int j;

							/* Get triagnle uvs	*/
							copy_v2_v2(uv1co, mloopuv[mlooptri[i].tri[0]].uv);
							copy_v2_v2(uv2co, mloopuv[mlooptri[i].tri[1]].uv);
							copy_v2_v2(uv3co, mloopuv[mlooptri[i].tri[2]].uv);

							/* Add b-weights per anti-aliasing sample	*/
							for (j = 0; j < aa_samples; j++) {
								uv[0] = point[0][0] + jitter5sample[j * 2] / w;
								uv[1] = point[0][1] + jitter5sample[j * 2 + 1] / h;

								barycentric_weights_v2(uv1co, uv2co, uv3co, uv, tempWeights[index * aa_samples + j].v);
							}

							/* Set surface point face values	*/
							tPoint->tri_index = i;

							/* save vertex indexes	*/
							tPoint->v1 = mloop[mlooptri[i].tri[0]].v;
							tPoint->v2 = mloop[mlooptri[i].tri[1]].v;
							tPoint->v3 = mloop[mlooptri[i].tri[2]].v;

							sample = 5; /* make sure we exit sample loop as well */
							break;
						}
					}
				} /* sample loop */
			}
		}

		/*
		 *	Now loop through every pixel that was left without index
		 *	and find if they have neighboring pixels that have an index.
		 *	If so use that polygon as pixel surface.
		 *	(To avoid seams on uv island edges)
		 */
#pragma omp parallel for schedule(static)
		for (ty = 0; ty < h; ty++) {
			int tx;
			for (tx = 0; tx < w; tx++) {
				int index = tx + w * ty;
				PaintUVPoint *tPoint = (&tempPoints[index]);

				/* If point isn't't on canvas mesh	*/
				if (tPoint->tri_index == -1) {
					int u_min, u_max, v_min, v_max;
					int u, v, ind;
					float point[2];

					/* get loop area	*/
					u_min = (tx > 0) ? -1 : 0;
					u_max = (tx < (w - 1)) ? 1 : 0;
					v_min = (ty > 0) ? -1 : 0;
					v_max = (ty < (h - 1)) ? 1 : 0;

					point[0] = ((float)tx + 0.5f) / w;
					point[1] = ((float)ty + 0.5f) / h;

					/* search through defined area for neighbor	*/
					for (u = u_min; u <= u_max; u++)
						for (v = v_min; v <= v_max; v++) {
							/* if not this pixel itself	*/
							if (u != 0 || v != 0) {
								ind = (tx + u) + w * (ty + v);

								/* if neighbor has index	*/
								if (tempPoints[ind].tri_index != -1) {

									float uv1co[2], uv2co[2], uv3co[2], uv[2];
									int i = tempPoints[ind].tri_index, j;

									/* Now calculate pixel data for this pixel as it was on polygon surface */
									copy_v2_v2(uv1co, mloopuv[mlooptri[i].tri[0]].uv);
									copy_v2_v2(uv2co, mloopuv[mlooptri[i].tri[1]].uv);
									copy_v2_v2(uv3co, mloopuv[mlooptri[i].tri[2]].uv);

									/* Add b-weights per anti-aliasing sample	*/
									for (j = 0; j < aa_samples; j++) {

										uv[0] = point[0] + jitter5sample[j * 2] / w;
										uv[1] = point[1] + jitter5sample[j * 2 + 1] / h;
										barycentric_weights_v2(uv1co, uv2co, uv3co, uv, tempWeights[index * aa_samples + j].v);
									}

									/* Set values	*/
									tPoint->neighbour_pixel = ind;  /* tri index */

									/* save vertex indexes	*/
									tPoint->v1 = mloop[mlooptri[i].tri[0]].v;
									tPoint->v2 = mloop[mlooptri[i].tri[1]].v;
									tPoint->v3 = mloop[mlooptri[i].tri[2]].v;

									u = u_max + 1;  /* make sure we exit outer loop as well */
									break;
								}
							}
						}
				}
			}
		}

		/*
		 *	When base loop is over convert found neighbor indexes to real ones
		 *	Also count the final number of active surface points
		 */
		for (ty = 0; ty < h; ty++) {
			int tx;
			for (tx = 0; tx < w; tx++) {
				int index = tx + w * ty;
				PaintUVPoint *tPoint = &tempPoints[index];

				if (tPoint->tri_index == -1 && tPoint->neighbour_pixel != -1)
					tPoint->tri_index = tempPoints[tPoint->neighbour_pixel].tri_index;
				if (tPoint->tri_index != -1)
					active_points++;
			}
		}

		/*	Generate surface adjacency data. */
		{
			int i, cursor = 0;

			/* Create a temporary array of final indexes (before unassigned
			 *  pixels have been dropped) */
			for (i = 0; i < w * h; i++) {
				if (tempPoints[i].tri_index != -1) {
					final_index[i] = cursor;
					cursor++;
				}
			}
			/* allocate memory */
			sData->total_points = w * h;
			dynamicPaint_initAdjacencyData(surface, 1);

			if (sData->adj_data) {
				PaintAdjData *ed = sData->adj_data;
				unsigned int n_pos = 0;
				for (ty = 0; ty < h; ty++) {
					int tx;
					for (tx = 0; tx < w; tx++) {
						int i, index = tx + w * ty;

						if (tempPoints[index].tri_index != -1) {
							ed->n_index[final_index[index]] = n_pos;
							ed->n_num[final_index[index]] = 0;

							for (i = 0; i < 8; i++) {

								/* Try to find a neighboring pixel in defined direction
								 *  If not found, -1 is returned */
								int n_target = dynamicPaint_findNeighbourPixel(tempPoints, dm, uvname, w, h, tx, ty, i);

								if (n_target >= 0) {
									ed->n_target[n_pos] = final_index[n_target];
									ed->n_num[final_index[index]]++;
									n_pos++;
								}
								else if (n_target == ON_MESH_EDGE || n_target == OUT_OF_TEXTURE) {
									ed->flags[final_index[index]] |= ADJ_ON_MESH_EDGE;
								}
							}
						}
					}
				}
			}
		}

		/* Create final surface data without inactive points */
		{
			ImgSeqFormatData *f_data = MEM_callocN(sizeof(struct ImgSeqFormatData), "ImgSeqFormatData");
			if (f_data) {
				f_data->uv_p = MEM_callocN(active_points * sizeof(struct PaintUVPoint), "PaintUVPoint");
				f_data->barycentricWeights = MEM_callocN(active_points * aa_samples * sizeof(struct Vec3f), "PaintUVPoint");

				if (!f_data->uv_p || !f_data->barycentricWeights) error = 1;
			}
			else {
				error = 1;
			}

			sData->total_points = active_points;
			
			/* in case of allocation error, free everything */
			if (error) {
				if (f_data) {
					if (f_data->uv_p) MEM_freeN(f_data->uv_p);
					if (f_data->barycentricWeights) MEM_freeN(f_data->barycentricWeights);
					MEM_freeN(f_data);
				}
			}
			else {
				int index, cursor = 0;
				sData->total_points = active_points;
				sData->format_data = f_data;

				for (index = 0; index < (w * h); index++) {
					if (tempPoints[index].tri_index != -1) {
						memcpy(&f_data->uv_p[cursor], &tempPoints[index], sizeof(PaintUVPoint));
						memcpy(&f_data->barycentricWeights[cursor * aa_samples], &tempWeights[index * aa_samples], sizeof(Vec3f) * aa_samples);
						cursor++;
					}
				}
			}
		}
	}
	if (error == 1)
		setError(canvas, N_("Not enough free memory"));

	if (faceBB) MEM_freeN(faceBB);
	if (tempPoints) MEM_freeN(tempPoints);
	if (tempWeights) MEM_freeN(tempWeights);
	if (final_index) MEM_freeN(final_index);

	/* Init surface type data */
	if (!error) {
		dynamicPaint_allocateSurfaceType(surface);

#if 0
		/*  -----------------------------------------------------------------
		 *	For debug, output pixel statuses to the color map
		 *	-----------------------------------------------------------------*/
#pragma omp parallel for schedule(static)
		for (index = 0; index < sData->total_points; index++)
		{
			ImgSeqFormatData *f_data = (ImgSeqFormatData *)sData->format_data;
			PaintUVPoint *uvPoint = &((PaintUVPoint *)f_data->uv_p)[index];
			PaintPoint *pPoint = &((PaintPoint *)sData->type_data)[index];
			pPoint->alpha = 1.0f;

			/* Every pixel that is assigned as "edge pixel" gets blue color	*/
			if (uvPoint->neighbour_pixel != -1) pPoint->color[2] = 1.0f;
			/* and every pixel that finally got an polygon gets red color	*/
			if (uvPoint->tri_index != -1) pPoint->color[0] = 1.0f;
			/* green color shows pixel face index hash	*/
			if (uvPoint->tri_index != -1) pPoint->color[1] = (float)(uvPoint->tri_index % 255) / 256.0f;
		}

#endif
		dynamicPaint_setInitialColor(scene, surface);
	}

	return (error == 0);
}

/*
 *	Outputs an image file from uv surface data.
 */
void dynamicPaint_outputSurfaceImage(DynamicPaintSurface *surface, char *filename, short output_layer)
{
	int index;
	ImBuf *ibuf = NULL;
	PaintSurfaceData *sData = surface->data;
	ImgSeqFormatData *f_data = (ImgSeqFormatData *)sData->format_data;
	/* OpenEXR or PNG	*/
	int format = (surface->image_fileformat & MOD_DPAINT_IMGFORMAT_OPENEXR) ? R_IMF_IMTYPE_OPENEXR : R_IMF_IMTYPE_PNG;
	char output_file[FILE_MAX];

	if (!sData->type_data) {
		setError(surface->canvas, N_("Image save failed: invalid surface"));
		return;
	}
	/* if selected format is openexr, but current build doesnt support one */
#ifndef WITH_OPENEXR
	if (format == R_IMF_IMTYPE_OPENEXR) format = R_IMF_IMTYPE_PNG;
#endif
	BLI_strncpy(output_file, filename, sizeof(output_file));
	BKE_image_path_ensure_ext_from_imtype(output_file, format);

	/* Validate output file path	*/
	BLI_path_abs(output_file, G.main->name);
	BLI_make_existing_file(output_file);

	/* Init image buffer	*/
	ibuf = IMB_allocImBuf(surface->image_resolution, surface->image_resolution, 32, IB_rectfloat);
	if (ibuf == NULL) {
		setError(surface->canvas, N_("Image save failed: not enough free memory"));
		return;
	}

#pragma omp parallel for schedule(static)
	for (index = 0; index < sData->total_points; index++) {
		int pos = f_data->uv_p[index].pixel_index * 4;  /* image buffer position */

		/* Set values of preferred type */
		if (output_layer == 1) {
			/* wetmap */
			if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
				PaintPoint *point = &((PaintPoint *)sData->type_data)[index];
				float value = (point->wetness > 1.0f) ? 1.0f : point->wetness;

				ibuf->rect_float[pos] = value;
				ibuf->rect_float[pos + 1] = value;
				ibuf->rect_float[pos + 2] = value;
				ibuf->rect_float[pos + 3] = 1.0f;
			}
		}
		else if (output_layer == 0) {
			/* Paintmap */
			if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
				PaintPoint *point = &((PaintPoint *)sData->type_data)[index];

				/* blend wet and dry layers */
				blendColors(point->color, point->color[3], point->e_color, point->e_color[3], &ibuf->rect_float[pos]);

				/* Multiply color by alpha if enabled	*/
				if (surface->flags & MOD_DPAINT_MULALPHA) {
					ibuf->rect_float[pos]   *= ibuf->rect_float[pos + 3];
					ibuf->rect_float[pos + 1] *= ibuf->rect_float[pos + 3];
					ibuf->rect_float[pos + 2] *= ibuf->rect_float[pos + 3];
				}
			}
			/* displace */
			else if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE) {
				float depth = ((float *)sData->type_data)[index];
				if (surface->depth_clamp)
					depth /= surface->depth_clamp;

				if (surface->disp_type == MOD_DPAINT_DISP_DISPLACE) {
					depth = (0.5f - depth / 2.0f);
				}

				CLAMP(depth, 0.0f, 1.0f);

				ibuf->rect_float[pos] = depth;
				ibuf->rect_float[pos + 1] = depth;
				ibuf->rect_float[pos + 2] = depth;
				ibuf->rect_float[pos + 3] = 1.0f;
			}
			/* waves */
			else if (surface->type == MOD_DPAINT_SURFACE_T_WAVE) {
				PaintWavePoint *wPoint = &((PaintWavePoint *)sData->type_data)[index];
				float depth = wPoint->height;
				if (surface->depth_clamp)
					depth /= surface->depth_clamp;
				depth = (0.5f + depth / 2.0f);
				CLAMP(depth, 0.0f, 1.0f);

				ibuf->rect_float[pos] = depth;
				ibuf->rect_float[pos + 1] = depth;
				ibuf->rect_float[pos + 2] = depth;
				ibuf->rect_float[pos + 3] = 1.0f;
			}
		}
	}

	/* Set output format, png in case exr isn't supported */
	ibuf->ftype = IMB_FTYPE_PNG;
	ibuf->foptions.quality = 15;

#ifdef WITH_OPENEXR
	if (format == R_IMF_IMTYPE_OPENEXR) {   /* OpenEXR 32-bit float */
		ibuf->ftype = IMB_FTYPE_OPENEXR;
		ibuf->foptions.flag |= OPENEXR_COMPRESS;
	}
#endif

	/* Save image */
	IMB_saveiff(ibuf, output_file, IB_rectfloat);
	IMB_freeImBuf(ibuf);
}


/***************************** Material / Texture Sampling ******************************/

/* stores a copy of required materials to allow doing adjustments
 *  without interfering the render/preview */
typedef struct BrushMaterials {
	Material *mat;
	Material **ob_mats;
	int tot;
} BrushMaterials;

/* Initialize materials for brush object:
 *  Calculates inverse matrices for linked objects, updates
 *  volume caches etc. */
static void dynamicPaint_updateBrushMaterials(Object *brushOb, Material *ui_mat, Scene *scene, BrushMaterials *bMats)
{
	/* Calculate inverse transformation matrix
	 *  for this object */
	invert_m4_m4(brushOb->imat, brushOb->obmat);
	copy_m4_m4(brushOb->imat_ren, brushOb->imat);

	/* Now process every material linked to this brush object */
	if ((ui_mat == NULL) && brushOb->mat && brushOb->totcol) {
		int i, tot = (*give_totcolp(brushOb));

		/* allocate material pointer array */
		if (tot) {
			bMats->ob_mats = MEM_callocN(sizeof(Material *) * (tot), "BrushMaterials");
			for (i = 0; i < tot; i++) {
				bMats->ob_mats[i] = RE_init_sample_material(give_current_material(brushOb, (i + 1)), scene);
			}
		}
		bMats->tot = tot;
	}
	else {
		bMats->mat = RE_init_sample_material(ui_mat, scene);
	}
}

/* free all data allocated by dynamicPaint_updateBrushMaterials() */
static void dynamicPaint_freeBrushMaterials(BrushMaterials *bMats)
{
	/* Now process every material linked to this brush object */
	if (bMats->ob_mats) {
		int i;
		for (i = 0; i < bMats->tot; i++) {
			RE_free_sample_material(bMats->ob_mats[i]);
		}
		MEM_freeN(bMats->ob_mats);
	}
	else if (bMats->mat) {
		RE_free_sample_material(bMats->mat);
	}
}

/*
 *	Get material diffuse color and alpha (including linked textures) in given coordinates
 */
static void dynamicPaint_doMaterialTex(
        BrushMaterials *bMats, float color[3], float *alpha, Object *brushOb,
        const float volume_co[3], const float surface_co[3],
        int triIndex, DerivedMesh *orcoDm)
{
	Material *mat = bMats->mat;

	const MLoopTri *mlooptri = orcoDm->getLoopTriArray(orcoDm);
	const MPoly *mpoly = orcoDm->getPolyArray(orcoDm);

	/* If no material defined, use the one assigned to the mesh face */
	if (mat == NULL) {
		if (bMats->ob_mats) {
			int mat_nr = mpoly[mlooptri[triIndex].poly].mat_nr;
			if (mat_nr >= (*give_totcolp(brushOb))) return;
			mat = bMats->ob_mats[mat_nr];
			if (mat == NULL) return;    /* No material assigned */
		}
		else {
			return;
		}
	}
	RE_sample_material_color(mat, color, alpha, volume_co, surface_co, triIndex, orcoDm, brushOb);
}


/***************************** Ray / Nearest Point Utils ******************************/


/*  A modified callback to bvh tree raycast. The tree must bust have been built using bvhtree_from_mesh_looptri.
 *   userdata must be a BVHMeshCallbackUserdata built from the same mesh as the tree.
 *
 *	To optimize brush detection speed this doesn't calculate hit coordinates or normal.
 */
static void mesh_tris_spherecast_dp(void *userdata, int index, const BVHTreeRay *ray, BVHTreeRayHit *hit)
{
	const BVHTreeFromMesh *data = (BVHTreeFromMesh *) userdata;
	const MVert *vert = data->vert;
	const MLoopTri *mlooptri = data->looptri;
	const MLoop *mloop = data->loop;

	const float *t0, *t1, *t2;
	float dist;

	t0 = vert[mloop[mlooptri[index].tri[0]].v].co;
	t1 = vert[mloop[mlooptri[index].tri[1]].v].co;
	t2 = vert[mloop[mlooptri[index].tri[2]].v].co;

	dist = bvhtree_ray_tri_intersection(ray, hit->dist, t0, t1, t2);

	if (dist >= 0 && dist < hit->dist) {
		hit->index = index;
		hit->dist = dist;
		hit->no[0] = 0.0f;
	}

}

/* A modified callback to bvh tree nearest point. The tree must bust have been built using bvhtree_from_mesh_looptri.
 *  userdata must be a BVHMeshCallbackUserdata built from the same mesh as the tree.
 *
 *	To optimize brush detection speed this doesn't calculate hit normal.
 */
static void mesh_tris_nearest_point_dp(void *userdata, int index, const float co[3], BVHTreeNearest *nearest)
{
	const BVHTreeFromMesh *data = (BVHTreeFromMesh *) userdata;
	const MVert *vert = data->vert;
	const MLoopTri *mlooptri = data->looptri;
	const MLoop *mloop = data->loop;
	float nearest_tmp[3], dist_sq;

	const float *t0, *t1, *t2;
	t0 = vert[mloop[mlooptri[index].tri[0]].v].co;
	t1 = vert[mloop[mlooptri[index].tri[1]].v].co;
	t2 = vert[mloop[mlooptri[index].tri[2]].v].co;

	closest_on_tri_to_point_v3(nearest_tmp, co, t0, t1, t2);
	dist_sq = len_squared_v3v3(co, nearest_tmp);

	if (dist_sq < nearest->dist_sq) {
		nearest->index = index;
		nearest->dist_sq = dist_sq;
		copy_v3_v3(nearest->co, nearest_tmp);
		nearest->no[0] = 0.0f;
	}
}


/***************************** Brush Painting Calls ******************************/

/**
 * Mix color values to canvas point.
 *
 * \param surface: Canvas surface
 * \param index: Surface point index
 * \param paintFlags: paint object flags
 * \param paintColor,paintAlpha,paintWetness: To be mixed paint values
 * \param timescale: Value used to adjust time dependent
 * operations when using substeps
 */
static void dynamicPaint_mixPaintColors(
        DynamicPaintSurface *surface, int index, int paintFlags,
        const float paintColor[3], float *paintAlpha, float *paintWetness, float *timescale)
{
	PaintPoint *pPoint = &((PaintPoint *)surface->data->type_data)[index];

	/* Add paint	*/
	if (!(paintFlags & MOD_DPAINT_ERASE)) {
		float mix[4];
		float temp_alpha = (*paintAlpha) * ((paintFlags & MOD_DPAINT_ABS_ALPHA) ? 1.0f : (*timescale));

		/* mix brush color with wet layer color */
		blendColors(pPoint->e_color, pPoint->e_color[3], paintColor, temp_alpha, mix);
		copy_v3_v3(pPoint->e_color, mix);

		/* mix wetness and alpha depending on selected alpha mode */
		if (paintFlags & MOD_DPAINT_ABS_ALPHA) {
			/* update values to the brush level unless theyre higher already */
			CLAMP_MIN(pPoint->e_color[3], *paintAlpha);
			CLAMP_MIN(pPoint->wetness, *paintWetness);
		}
		else {
			float wetness = (*paintWetness);
			CLAMP(wetness, 0.0f, 1.0f);
			pPoint->e_color[3] = mix[3];
			pPoint->wetness = pPoint->wetness * (1.0f - wetness) + wetness;
		}

		CLAMP_MIN(pPoint->wetness, MIN_WETNESS);

		pPoint->state = DPAINT_PAINT_NEW;
	}
	/* Erase paint	*/
	else {
		float a_ratio, a_highest;
		float wetness;
		float invFact = 1.0f - (*paintAlpha);

		/*
		 *	Make highest alpha to match erased value
		 *	but maintain alpha ratio
		 */
		if (paintFlags & MOD_DPAINT_ABS_ALPHA) {
			a_highest = max_ff(pPoint->color[3], pPoint->e_color[3]);
			if (a_highest > invFact) {
				a_ratio = invFact / a_highest;

				pPoint->e_color[3] *= a_ratio;
				pPoint->color[3] *= a_ratio;
			}
		}
		else {
			pPoint->e_color[3] -= (*paintAlpha) * (*timescale);
			CLAMP_MIN(pPoint->e_color[3], 0.0f);
			pPoint->color[3] -= (*paintAlpha) * (*timescale);
			CLAMP_MIN(pPoint->color[3], 0.0f);
		}

		wetness = (1.0f - (*paintWetness)) * pPoint->e_color[3];
		CLAMP_MAX(pPoint->wetness, wetness);
	}
}

/* applies given brush intersection value for wave surface */
static void dynamicPaint_mixWaveHeight(PaintWavePoint *wPoint, DynamicPaintBrushSettings *brush, float isect_height)
{
	float isect_change = isect_height - wPoint->brush_isect;
	int hit = 0;
	/* intersection marked regardless of brush type or hit */
	wPoint->brush_isect = isect_height;
	wPoint->state = DPAINT_WAVE_ISECT_CHANGED;

	isect_height *= brush->wave_factor;

	/* determine hit depending on wave_factor */
	if (brush->wave_factor > 0.0f && wPoint->height > isect_height)
		hit = 1;
	else if (brush->wave_factor < 0.0f && wPoint->height < isect_height)
		hit = 1;

	if (hit) {
		if (brush->wave_type == MOD_DPAINT_WAVEB_DEPTH) {
			wPoint->height = isect_height;
			wPoint->state = DPAINT_WAVE_OBSTACLE;
			wPoint->velocity = 0.0f;
		}
		else if (brush->wave_type == MOD_DPAINT_WAVEB_FORCE)
			wPoint->velocity = isect_height;
		else if (brush->wave_type == MOD_DPAINT_WAVEB_REFLECT)
			wPoint->state = DPAINT_WAVE_REFLECT_ONLY;
		else if (brush->wave_type == MOD_DPAINT_WAVEB_CHANGE) {
			if (isect_change < 0.0f)
				wPoint->height += isect_change * brush->wave_factor;
		}
	}
}

/*
 *	add brush results to the surface data depending on surface type
 */
static void dynamicPaint_updatePointData(DynamicPaintSurface *surface, unsigned int index, DynamicPaintBrushSettings *brush,
                                         float paint[3], float influence, float depth, float vel_factor, float timescale)
{
	PaintSurfaceData *sData = surface->data;
	float strength;

	/* apply influence scale */
	influence *= surface->influence_scale;
	depth *= surface->influence_scale;

	strength = influence * brush->alpha;
	CLAMP(strength, 0.0f, 1.0f);

	/* Sample velocity colorband if required */
	if (brush->flags & (MOD_DPAINT_VELOCITY_ALPHA | MOD_DPAINT_VELOCITY_COLOR | MOD_DPAINT_VELOCITY_DEPTH)) {
		float coba_res[4];
		vel_factor /= brush->max_velocity;
		CLAMP(vel_factor, 0.0f, 1.0f);

		if (do_colorband(brush->vel_ramp, vel_factor, coba_res)) {
			if (brush->flags & MOD_DPAINT_VELOCITY_COLOR) {
				paint[0] = coba_res[0];
				paint[1] = coba_res[1];
				paint[2] = coba_res[2];
			}
			if (brush->flags & MOD_DPAINT_VELOCITY_ALPHA)
				strength *= coba_res[3];
			if (brush->flags & MOD_DPAINT_VELOCITY_DEPTH)
				depth *= coba_res[3];
		}
	}

	/* mix paint surface */
	if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {

		float paintWetness = brush->wetness * strength;
		float paintAlpha = strength;

		dynamicPaint_mixPaintColors(surface, index, brush->flags, paint, &paintAlpha, &paintWetness, &timescale);

	}
	/* displace surface */
	else if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE) {
		float *value = (float *)sData->type_data;

		if (surface->flags & MOD_DPAINT_DISP_INCREMENTAL)
			depth = value[index] + depth;

		if (surface->depth_clamp) {
			CLAMP(depth, 0.0f - surface->depth_clamp, surface->depth_clamp);
		}

		if (brush->flags & MOD_DPAINT_ERASE) {
			value[index] *= (1.0f - strength);
			if (value[index] < 0.0f) value[index] = 0.0f;
		}
		else {
			if (value[index] < depth) value[index] = depth;
		}
	}
	/* vertex weight group surface */
	else if (surface->type == MOD_DPAINT_SURFACE_T_WEIGHT) {
		float *value = (float *)sData->type_data;

		if (brush->flags & MOD_DPAINT_ERASE) {
			value[index] *= (1.0f - strength);
			if (value[index] < 0.0f) value[index] = 0.0f;
		}
		else {
			if (value[index] < strength) value[index] = strength;
		}
	}
	/* wave surface */
	else if (surface->type == MOD_DPAINT_SURFACE_T_WAVE) {
		if (brush->wave_clamp) {
			CLAMP(depth, 0.0f - brush->wave_clamp, brush->wave_clamp);
		}

		dynamicPaint_mixWaveHeight(&((PaintWavePoint *)sData->type_data)[index],
		                           brush, 0.0f - depth);
	}

	/* doing velocity based painting */
	if (sData->bData->brush_velocity) {
		sData->bData->brush_velocity[index * 4 + 3] *= influence;
	}
}

/* checks whether surface and brush bounds intersect depending on brush type */
static int meshBrush_boundsIntersect(Bounds3D *b1, Bounds3D *b2, DynamicPaintBrushSettings *brush, float brush_radius)
{
	if (brush->collision == MOD_DPAINT_COL_VOLUME)
		return boundsIntersect(b1, b2);
	else if (brush->collision == MOD_DPAINT_COL_DIST || brush->collision == MOD_DPAINT_COL_VOLDIST)
		return boundsIntersectDist(b1, b2, brush_radius);
	else return 1;
}

/* calculate velocity for mesh vertices */
static void dynamicPaint_brushMeshCalculateVelocity(Scene *scene, Object *ob, DynamicPaintBrushSettings *brush, Vec3f **brushVel, float timescale)
{
	int i;
	float prev_obmat[4][4];
	DerivedMesh *dm_p, *dm_c;
	MVert *mvert_p, *mvert_c;
	int numOfVerts_p, numOfVerts_c;

	float cur_sfra = scene->r.subframe;
	int cur_fra = scene->r.cfra;
	float prev_sfra = cur_sfra - timescale;
	int prev_fra = cur_fra;

	if (prev_sfra < 0.0f) {
		prev_sfra += 1.0f;
		prev_fra = cur_fra - 1;
	}

	/* previous frame dm */
	scene->r.cfra = prev_fra;
	scene->r.subframe = prev_sfra;

	subframe_updateObject(scene, ob, UPDATE_EVERYTHING, SUBFRAME_RECURSION, BKE_scene_frame_get(scene));
	dm_p = CDDM_copy(brush->dm);
	numOfVerts_p = dm_p->getNumVerts(dm_p);
	mvert_p = dm_p->getVertArray(dm_p);
	copy_m4_m4(prev_obmat, ob->obmat);

	/* current frame dm */
	scene->r.cfra = cur_fra;
	scene->r.subframe = cur_sfra;

	subframe_updateObject(scene, ob, UPDATE_EVERYTHING, SUBFRAME_RECURSION, BKE_scene_frame_get(scene));
	dm_c = brush->dm;
	numOfVerts_c = dm_c->getNumVerts(dm_c);
	mvert_c = dm_p->getVertArray(dm_c);

	(*brushVel) = (struct Vec3f *) MEM_mallocN(numOfVerts_c * sizeof(Vec3f), "Dynamic Paint brush velocity");
	if (!(*brushVel)) return;

	/* if mesh is constructive -> num of verts has changed,
	 *  only use current frame derived mesh */
	if (numOfVerts_p != numOfVerts_c)
		mvert_p = mvert_c;

	/* calculate speed */
#pragma omp parallel for schedule(static)
	for (i = 0; i < numOfVerts_c; i++) {
		float p1[3], p2[3];

		copy_v3_v3(p1, mvert_p[i].co);
		mul_m4_v3(prev_obmat, p1);

		copy_v3_v3(p2, mvert_c[i].co);
		mul_m4_v3(ob->obmat, p2);

		sub_v3_v3v3((*brushVel)[i].v, p2, p1);
		mul_v3_fl((*brushVel)[i].v, 1.0f / timescale);
	}

	dm_p->release(dm_p);
}

/* calculate velocity for object center point */
static void dynamicPaint_brushObjectCalculateVelocity(Scene *scene, Object *ob, Vec3f *brushVel, float timescale)
{
	float prev_obmat[4][4];
	float cur_loc[3] = {0.0f}, prev_loc[3] = {0.0f};

	float cur_sfra = scene->r.subframe;
	int cur_fra = scene->r.cfra;
	float prev_sfra = cur_sfra - timescale;
	int prev_fra = cur_fra;

	if (prev_sfra < 0.0f) {
		prev_sfra += 1.0f;
		prev_fra = cur_fra - 1;
	}

	/* previous frame dm */
	scene->r.cfra = prev_fra;
	scene->r.subframe = prev_sfra;
	subframe_updateObject(scene, ob, 0, SUBFRAME_RECURSION, BKE_scene_frame_get(scene));
	copy_m4_m4(prev_obmat, ob->obmat);

	/* current frame dm */
	scene->r.cfra = cur_fra;
	scene->r.subframe = cur_sfra;
	subframe_updateObject(scene, ob, 0, SUBFRAME_RECURSION, BKE_scene_frame_get(scene));

	/* calculate speed */
	mul_m4_v3(prev_obmat, prev_loc);
	mul_m4_v3(ob->obmat, cur_loc);

	sub_v3_v3v3(brushVel->v, cur_loc, prev_loc);
	mul_v3_fl(brushVel->v, 1.0f / timescale);
}

/*
 *	Paint a brush object mesh to the surface
 */
static int dynamicPaint_paintMesh(DynamicPaintSurface *surface,
                                  DynamicPaintBrushSettings *brush,
                                  Object *brushOb,
                                  BrushMaterials *bMats,
                                  Scene *scene,
                                  float timescale)
{
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	DerivedMesh *dm = NULL;
	Vec3f *brushVelocity = NULL;
	MVert *mvert = NULL;
	const MLoopTri *mlooptri = NULL;
	const MLoop *mloop = NULL;

	if (brush->flags & MOD_DPAINT_USES_VELOCITY)
		dynamicPaint_brushMeshCalculateVelocity(scene, brushOb, brush, &brushVelocity, timescale);

	if (!brush->dm) return 0;
	{
		BVHTreeFromMesh treeData = {NULL};
		float avg_brushNor[3] = {0.0f};
		float brush_radius = brush->paint_distance * surface->radius_scale;
		int numOfVerts;
		int ii;
		Bounds3D mesh_bb = {0};
		VolumeGrid *grid = bData->grid;

		dm = CDDM_copy(brush->dm);
		mvert = dm->getVertArray(dm);
		mlooptri = dm->getLoopTriArray(dm);
		mloop = dm->getLoopArray(dm);
		numOfVerts = dm->getNumVerts(dm);

		/*	Transform collider vertices to global space
		 *	(Faster than transforming per surface point
		 *	coordinates and normals to object space) */
		for (ii = 0; ii < numOfVerts; ii++) {
			mul_m4_v3(brushOb->obmat, mvert[ii].co);
			boundInsert(&mesh_bb, mvert[ii].co);

			/* for proximity project calculate average normal */
			if (brush->flags & MOD_DPAINT_PROX_PROJECT && brush->collision != MOD_DPAINT_COL_VOLUME) {
				float nor[3];
				normal_short_to_float_v3(nor, mvert[ii].no);
				mul_mat3_m4_v3(brushOb->obmat, nor);
				normalize_v3(nor);

				add_v3_v3(avg_brushNor, nor);
			}
		}

		if (brush->flags & MOD_DPAINT_PROX_PROJECT && brush->collision != MOD_DPAINT_COL_VOLUME) {
			mul_v3_fl(avg_brushNor, 1.0f / (float)numOfVerts);
			/* instead of null vector use positive z */
			if (UNLIKELY(normalize_v3(avg_brushNor) == 0.0f)) {
				avg_brushNor[2] = 1.0f;
			}
		}

		/* check bounding box collision */
		if (grid && meshBrush_boundsIntersect(&grid->grid_bounds, &mesh_bb, brush, brush_radius)) {
			/* Build a bvh tree from transformed vertices	*/
			if (bvhtree_from_mesh_looptri(&treeData, dm, 0.0f, 4, 8)) {
				int c_index;
				int total_cells = grid->dim[0] * grid->dim[1] * grid->dim[2];

				/* loop through space partitioning grid */
				for (c_index = 0; c_index < total_cells; c_index++) {
					int id;

					/* check grid cell bounding box */
					if (!grid->s_num[c_index] || !meshBrush_boundsIntersect(&grid->bounds[c_index], &mesh_bb, brush, brush_radius))
						continue;

					/* loop through cell points and process brush */
#pragma omp parallel for schedule(static)
					for (id = 0; id < grid->s_num[c_index]; id++) {
						int index = grid->t_index[grid->s_pos[c_index] + id];
						int ss, samples = bData->s_num[index];
						float total_sample = (float)samples;
						float brushStrength = 0.0f; /* brush influence factor */
						float depth = 0.0f; /* brush intersection depth */
						float velocity_val = 0.0f;

						float paintColor[3] = {0.0f};
						int numOfHits = 0;

						/* for image sequence anti-aliasing, use gaussian factors */
						if (samples > 1 && surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ)
							total_sample = gaussianTotal;
					
						/* Supersampling	*/
						for (ss = 0; ss < samples; ss++) {

							float ray_start[3], ray_dir[3];
							float sample_factor = 0.0f;
							float sampleStrength = 0.0f;
							BVHTreeRayHit hit;
							BVHTreeNearest nearest;
							short hit_found = 0;

							/* volume sample */
							float volume_factor = 0.0f;
							/* proximity sample */
							float proximity_factor = 0.0f;
							float prox_colorband[4] = {0.0f};
							int inner_proximity = (brush->flags & MOD_DPAINT_INVERSE_PROX &&
							                       brush->collision == MOD_DPAINT_COL_VOLDIST);

							/* hit data	*/
							float hitCoord[3];
							int hitTri = -1;

							/* Supersampling factor	*/
							if (samples > 1 && surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ)
								sample_factor = gaussianFactors[ss];
							else
								sample_factor = 1.0f;

							/* Get current sample position in world coordinates	*/
							copy_v3_v3(ray_start, bData->realCoord[bData->s_pos[index] + ss].v);
							copy_v3_v3(ray_dir, bData->bNormal[index].invNorm);

							/* a simple hack to minimize chance of ray leaks at identical ray <-> edge locations */
							add_v3_fl(ray_start, 0.001f);

							hit.index = -1;
							hit.dist = 9999;
							nearest.index = -1;
							nearest.dist_sq = brush_radius * brush_radius; /* find_nearest uses squared distance */

							/* Check volume collision	*/
							if (brush->collision == MOD_DPAINT_COL_VOLUME || brush->collision == MOD_DPAINT_COL_VOLDIST)
								if (BLI_bvhtree_ray_cast(treeData.tree, ray_start, ray_dir, 0.0f, &hit, mesh_tris_spherecast_dp, &treeData) != -1) {
									/* We hit a triangle, now check if collision point normal is facing the point	*/

									/*	For optimization sake, hit point normal isn't calculated in ray cast loop	*/
									const int vtri[3] = {
									    mloop[mlooptri[hit.index].tri[0]].v,
									    mloop[mlooptri[hit.index].tri[1]].v,
									    mloop[mlooptri[hit.index].tri[2]].v,
									};
									float dot;

									normal_tri_v3(hit.no, mvert[vtri[0]].co, mvert[vtri[1]].co, mvert[vtri[2]].co);
									dot = dot_v3v3(ray_dir, hit.no);

									/*  If ray and hit face normal are facing same direction
									 *	hit point is inside a closed mesh. */
									if (dot >= 0) {
										float dist = hit.dist;
										int f_index = hit.index;

										/* Also cast a ray in opposite direction to make sure
										 * point is at least surrounded by two brush faces */
										negate_v3(ray_dir);
										hit.index = -1;
										hit.dist = 9999;

										BLI_bvhtree_ray_cast(treeData.tree, ray_start, ray_dir, 0.0f, &hit, mesh_tris_spherecast_dp, &treeData);

										if (hit.index != -1) {
											/* Add factor on supersample filter	*/
											volume_factor = 1.0f;
											hit_found = HIT_VOLUME;

											/* Mark hit info */
											madd_v3_v3v3fl(hitCoord, ray_start, ray_dir, hit.dist); /* Calculate final hit coordinates */
											depth += dist * sample_factor;
											hitTri = f_index;
										}
									}
								}

							/* Check proximity collision	*/
							if ((brush->collision == MOD_DPAINT_COL_DIST || brush->collision == MOD_DPAINT_COL_VOLDIST) &&
							    (!hit_found || (brush->flags & MOD_DPAINT_INVERSE_PROX)))
							{
								float proxDist = -1.0f;
								float hitCo[3] = {0.0f, 0.0f, 0.0f};
								int tri = 0;

								/* if inverse prox and no hit found, skip this sample */
								if (inner_proximity && !hit_found) continue;

								/* If pure distance proximity, find the nearest point on the mesh */
								if (!(brush->flags & MOD_DPAINT_PROX_PROJECT)) {
									if (BLI_bvhtree_find_nearest(treeData.tree, ray_start, &nearest, mesh_tris_nearest_point_dp, &treeData) != -1) {
										proxDist = sqrtf(nearest.dist_sq);
										copy_v3_v3(hitCo, nearest.co);
										tri = nearest.index;
									}
								}
								else { /* else cast a ray in defined projection direction */
									float proj_ray[3] = {0.0f};

									if (brush->ray_dir == MOD_DPAINT_RAY_CANVAS) {
										copy_v3_v3(proj_ray, bData->bNormal[index].invNorm);
										negate_v3(proj_ray);
									}
									else if (brush->ray_dir == MOD_DPAINT_RAY_BRUSH_AVG) {
										copy_v3_v3(proj_ray, avg_brushNor);
									}
									else { /* MOD_DPAINT_RAY_ZPLUS */
										proj_ray[2] = 1.0f;
									}
									hit.index = -1;
									hit.dist = brush_radius;

									/* Do a face normal directional raycast, and use that distance	*/
									if (BLI_bvhtree_ray_cast(treeData.tree, ray_start, proj_ray, 0.0f, &hit, mesh_tris_spherecast_dp, &treeData) != -1) {
										proxDist = hit.dist;
										madd_v3_v3v3fl(hitCo, ray_start, proj_ray, hit.dist); /* Calculate final hit coordinates */
										tri = hit.index;
									}
								}

								/* If a hit was found, calculate required values	*/
								if (proxDist >= 0.0f && proxDist <= brush_radius) {
									proximity_factor = proxDist / brush_radius;
									CLAMP(proximity_factor, 0.0f, 1.0f);
									if (!inner_proximity)
										proximity_factor = 1.0f - proximity_factor;

									hit_found = HIT_PROXIMITY;

									/* if no volume hit, use prox point face info */
									if (hitTri == -1) {
										copy_v3_v3(hitCoord, hitCo);
										hitTri = tri;
									}
								}
							}

							/* mix final sample strength depending on brush settings */
							if (hit_found) {
								/* if "negate volume" enabled, negate all factors within volume*/
								if (brush->collision == MOD_DPAINT_COL_VOLDIST && brush->flags & MOD_DPAINT_NEGATE_VOLUME) {
									volume_factor = 1.0f - volume_factor;
									if (inner_proximity)
										proximity_factor = 1.0f - proximity_factor;
								}

								/* apply final sample depending on final hit type */
								if (hit_found == HIT_VOLUME) {
									sampleStrength = volume_factor;
								}
								else if (hit_found == HIT_PROXIMITY) {
									/* apply falloff curve to the proximity_factor */
									if (brush->proximity_falloff == MOD_DPAINT_PRFALL_RAMP && do_colorband(brush->paint_ramp, (1.0f - proximity_factor), prox_colorband))
										proximity_factor = prox_colorband[3];
									else if (brush->proximity_falloff == MOD_DPAINT_PRFALL_CONSTANT)
										proximity_factor = (!inner_proximity || brush->flags & MOD_DPAINT_NEGATE_VOLUME) ? 1.0f : 0.0f;
									/* apply sample */
									sampleStrength = proximity_factor;
								}

								sampleStrength *= sample_factor;
							}
							else {
								continue;
							}

							/* velocity brush, only do on main sample */
							if (brush->flags & MOD_DPAINT_USES_VELOCITY && ss == 0 && brushVelocity) {
								int v1, v2, v3;
								float weights[4];
								float brushPointVelocity[3];
								float velocity[3];

								v1 = mloop[mlooptri[hitTri].tri[0]].v;
								v2 = mloop[mlooptri[hitTri].tri[1]].v;
								v3 = mloop[mlooptri[hitTri].tri[2]].v;

								/* calculate barycentric weights for hit point */
								interp_weights_face_v3(weights, mvert[v1].co, mvert[v2].co, mvert[v3].co, NULL, hitCoord);

								/* simple check based on brush surface velocity,
								 *  todo: perhaps implement something that handles volume movement as well */
							
								/* interpolate vertex speed vectors to get hit point velocity */
								interp_v3_v3v3v3(brushPointVelocity,
								                 brushVelocity[v1].v,
								                 brushVelocity[v2].v,
								                 brushVelocity[v3].v, weights);

								/* substract canvas point velocity */
								if (bData->velocity) {
									sub_v3_v3v3(velocity, brushPointVelocity, bData->velocity[index].v);
								}
								else {
									copy_v3_v3(velocity, brushPointVelocity);
								}
								velocity_val = len_v3(velocity);

								/* if brush has smudge enabled store brush velocity */
								if (surface->type == MOD_DPAINT_SURFACE_T_PAINT &&
								    brush->flags & MOD_DPAINT_DO_SMUDGE && bData->brush_velocity)
								{
									copy_v3_v3(&bData->brush_velocity[index * 4], velocity);
									mul_v3_fl(&bData->brush_velocity[index * 4], 1.0f / velocity_val);
									bData->brush_velocity[index * 4 + 3] = velocity_val;
								}
							}

							/*
							 *	Process hit color and alpha
							 */
							if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
								float sampleColor[3];
								float alpha_factor = 1.0f;

								sampleColor[0] = brush->r;
								sampleColor[1] = brush->g;
								sampleColor[2] = brush->b;

								/* Get material+textures color on hit point if required	*/
								if (brush_usesMaterial(brush, scene))
									dynamicPaint_doMaterialTex(bMats, sampleColor, &alpha_factor, brushOb, bData->realCoord[bData->s_pos[index] + ss].v, hitCoord, hitTri, brush->dm);

								/* Sample proximity colorband if required	*/
								if ((hit_found == HIT_PROXIMITY) && (brush->proximity_falloff == MOD_DPAINT_PRFALL_RAMP)) {
									if (!(brush->flags & MOD_DPAINT_RAMP_ALPHA)) {
										sampleColor[0] = prox_colorband[0];
										sampleColor[1] = prox_colorband[1];
										sampleColor[2] = prox_colorband[2];
									}
								}

								/* Add AA sample */
								paintColor[0] += sampleColor[0];
								paintColor[1] += sampleColor[1];
								paintColor[2] += sampleColor[2];
								sampleStrength *= alpha_factor;
								numOfHits++;
							}

							/* apply sample strength */
							brushStrength += sampleStrength;
						} // end supersampling


						/* if any sample was inside paint range	*/
						if (brushStrength > 0.0f || depth > 0.0f) {

							/* apply supersampling results	*/
							if (samples > 1) {
								brushStrength /= total_sample;
							}
							CLAMP(brushStrength, 0.0f, 1.0f);

							if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
								/* Get final pixel color and alpha	*/
								paintColor[0] /= numOfHits;
								paintColor[1] /= numOfHits;
								paintColor[2] /= numOfHits;
							}
							/* get final object space depth */
							else if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE ||
							         surface->type == MOD_DPAINT_SURFACE_T_WAVE)
							{
								depth /= bData->bNormal[index].normal_scale * total_sample;
							}

							dynamicPaint_updatePointData(surface, index, brush, paintColor, brushStrength, depth, velocity_val, timescale);
						}
					}
				}
			}
		}
		/* free bvh tree */
		free_bvhtree_from_mesh(&treeData);
		dm->release(dm);

	}

	/* free brush velocity data */
	if (brushVelocity)
		MEM_freeN(brushVelocity);

	return 1;
}

/*
 *	Paint a particle system to the surface
 */
static int dynamicPaint_paintParticles(DynamicPaintSurface *surface,
                                       ParticleSystem *psys,
                                       DynamicPaintBrushSettings *brush,
                                       float timescale)
{
	ParticleSettings *part = psys->part;
	ParticleData *pa = NULL;
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	VolumeGrid *grid = bData->grid; 

	KDTree *tree;
	int particlesAdded = 0;
	int invalidParticles = 0;
	int p = 0;

	float solidradius = surface->radius_scale * ((brush->flags & MOD_DPAINT_PART_RAD) ? psys->part->size : brush->particle_radius);
	float smooth = brush->particle_smooth * surface->radius_scale;

	float range = solidradius + smooth;
	float particle_timestep = 0.04f * part->timetweak;

	Bounds3D part_bb = {0};

	if (psys->totpart < 1) return 1;

	/*
	 *	Build a kd-tree to optimize distance search
	 */
	tree = BLI_kdtree_new(psys->totpart);

	/* loop through particles and insert valid ones	to the tree	*/
	for (p = 0, pa = psys->particles; p < psys->totpart; p++, pa++) {

		/* Proceed only if particle is active	*/
		if (pa->alive == PARS_UNBORN && (part->flag & PART_UNBORN) == 0) continue;
		else if (pa->alive == PARS_DEAD && (part->flag & PART_DIED) == 0) continue;
		else if (pa->flag & PARS_UNEXIST) continue;

		/*	for debug purposes check if any NAN particle proceeds
		 *	For some reason they get past activity check, this should rule most of them out	*/
		if (isnan(pa->state.co[0]) || isnan(pa->state.co[1]) || isnan(pa->state.co[2])) { invalidParticles++; continue; }

		/* make sure particle is close enough to canvas */
		if (!boundIntersectPoint(&grid->grid_bounds, pa->state.co, range)) continue;

		BLI_kdtree_insert(tree, p, pa->state.co);

		/* calc particle system bounds */
		boundInsert(&part_bb, pa->state.co);

		particlesAdded++;
	}
	if (invalidParticles)
		printf("Warning: Invalid particle(s) found!\n");

	/* If no suitable particles were found, exit	*/
	if (particlesAdded < 1) {
		BLI_kdtree_free(tree);
		return 1;
	}

	/* begin thread safe malloc */
	BLI_begin_threaded_malloc();

	/* only continue if particle bb is close enough to canvas bb */
	if (boundsIntersectDist(&grid->grid_bounds, &part_bb, range)) {
		int c_index;
		int total_cells = grid->dim[0] * grid->dim[1] * grid->dim[2];
		
		/* balance tree	*/
		BLI_kdtree_balance(tree);

		/* loop through space partitioning grid */
		for (c_index = 0; c_index < total_cells; c_index++) {
			int id;

			/* check cell bounding box */
			if (!grid->s_num[c_index] ||
			    !boundsIntersectDist(&grid->bounds[c_index], &part_bb, range))
			{
				continue;
			}

			/* loop through cell points */
#pragma omp parallel for schedule(static)
			for (id = 0; id < grid->s_num[c_index]; id++) {
				int index = grid->t_index[grid->s_pos[c_index] + id];
				float disp_intersect = 0.0f;
				float radius = 0.0f;
				float strength = 0.0f;
				float velocity_val = 0.0f;
				int part_index = -1;

				/*
				 *	With predefined radius, there is no variation between particles.
				 *	It's enough to just find the nearest one.
				 */
				{
					KDTreeNearest nearest;
					float smooth_range, part_solidradius;

					/* Find nearest particle and get distance to it	*/
					BLI_kdtree_find_nearest(tree, bData->realCoord[bData->s_pos[index]].v, &nearest);
					/* if outside maximum range, no other particle can influence either */
					if (nearest.dist > range) continue;

					if (brush->flags & MOD_DPAINT_PART_RAD) {
						/* use particles individual size */
						ParticleData *pa = psys->particles + nearest.index;
						part_solidradius = pa->size;
					}
					else {
						part_solidradius = solidradius;
					}
					radius = part_solidradius + smooth;
					if (nearest.dist < radius) {
						/* distances inside solid radius has maximum influence -> dist = 0	*/
						smooth_range = (nearest.dist - part_solidradius);
						if (smooth_range < 0.0f) smooth_range = 0.0f;
						/* do smoothness if enabled	*/
						if (smooth) smooth_range /= smooth;

						strength = 1.0f - smooth_range;
						disp_intersect = radius - nearest.dist;
						part_index = nearest.index;
					}
				}
				/* If using random per particle radius and closest particle didn't give max influence	*/
				if (brush->flags & MOD_DPAINT_PART_RAD && strength < 1.0f && psys->part->randsize > 0.0f) {
					/*
					 *	If we use per particle radius, we have to sample all particles
					 *	within max radius range
					 */
					KDTreeNearest *nearest;

					int n, particles;
					float smooth_range = smooth * (1.0f - strength), dist;
					/* calculate max range that can have particles with higher influence than the nearest one */
					float max_range = smooth - strength * smooth + solidradius;
					/* Make gcc happy! */
					dist = max_range;

					particles = BLI_kdtree_range_search(tree, bData->realCoord[bData->s_pos[index]].v,
					                                    &nearest, max_range);

					/* Find particle that produces highest influence */
					for (n = 0; n < particles; n++) {
						ParticleData *pa = psys->particles + nearest[n].index;
						float s_range;

						/* skip if out of range */
						if (nearest[n].dist > (pa->size + smooth))
							continue;

						/* update hit data */
						s_range = nearest[n].dist - pa->size;
						/* skip if higher influence is already found */
						if (smooth_range < s_range)
							continue;

						/* update hit data */
						smooth_range = s_range;
						dist = nearest[n].dist;
						part_index = nearest[n].index;

						/* If inside solid range and no disp depth required, no need to seek further */
						if ( (s_range < 0.0f) &&
						     (surface->type != MOD_DPAINT_SURFACE_T_DISPLACE) &&
						     (surface->type != MOD_DPAINT_SURFACE_T_WAVE))
						{
							break;
						}
					}

					if (nearest) MEM_freeN(nearest);

					/* now calculate influence for this particle */
					{
						float rad = radius + smooth, str;
						if ((rad - dist) > disp_intersect) {
							disp_intersect = radius - dist;
							radius = rad;
						}

						/* do smoothness if enabled	*/
						if (smooth_range < 0.0f) smooth_range = 0.0f;
						if (smooth) smooth_range /= smooth;
						str = 1.0f - smooth_range;
						/* if influence is greater, use this one	*/
						if (str > strength) strength = str;
					}
				}

				if (strength > 0.001f) {
					float paintColor[4] = {0.0f};
					float depth = 0.0f;

					/* apply velocity */
					if ((brush->flags & MOD_DPAINT_USES_VELOCITY) && (part_index != -1)) {
						float velocity[3];
						ParticleData *pa = psys->particles + part_index;
						mul_v3_v3fl(velocity, pa->state.vel, particle_timestep);

						/* substract canvas point velocity */
						if (bData->velocity) {
							sub_v3_v3(velocity, bData->velocity[index].v);
						}
						velocity_val = len_v3(velocity);

						/* store brush velocity for smudge */
						if ( (surface->type == MOD_DPAINT_SURFACE_T_PAINT) &&
						     (brush->flags & MOD_DPAINT_DO_SMUDGE && bData->brush_velocity))
						{
							copy_v3_v3(&bData->brush_velocity[index * 4], velocity);
							mul_v3_fl(&bData->brush_velocity[index * 4], 1.0f / velocity_val);
							bData->brush_velocity[index * 4 + 3] = velocity_val;
						}
					}

					if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
						copy_v3_v3(paintColor, &brush->r);
					}
					else if ( (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE) ||
					          (surface->type == MOD_DPAINT_SURFACE_T_WAVE))
					{
						/* get displace depth	*/
						disp_intersect = (1.0f - sqrtf(disp_intersect / radius)) * radius;
						depth = (radius - disp_intersect) / bData->bNormal[index].normal_scale;
						if (depth < 0.0f) depth = 0.0f;
					}
					
					dynamicPaint_updatePointData(surface, index, brush, paintColor, strength, depth, velocity_val, timescale);
				}
			}
		}
	}
	BLI_end_threaded_malloc();
	BLI_kdtree_free(tree);

	return 1;
}

/* paint a single point of defined proximity radius to the surface */
static int dynamicPaint_paintSinglePoint(DynamicPaintSurface *surface, float *pointCoord, DynamicPaintBrushSettings *brush,
                                         Object *brushOb, BrushMaterials *bMats, Scene *scene, float timescale)
{
	int index;
	float brush_radius = brush->paint_distance * surface->radius_scale;
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	Vec3f brushVel;

	if (brush->flags & MOD_DPAINT_USES_VELOCITY)
		dynamicPaint_brushObjectCalculateVelocity(scene, brushOb, &brushVel, timescale);

	/*
	 *	Loop through every surface point
	 */
#pragma omp parallel for schedule(static)
	for (index = 0; index < sData->total_points; index++) {
		float distance = len_v3v3(pointCoord, bData->realCoord[bData->s_pos[index]].v);
		float colorband[4] = {0.0f};
		float strength;

		if (distance > brush_radius) continue;

		/* Smooth range or color ramp	*/
		if (brush->proximity_falloff == MOD_DPAINT_PRFALL_SMOOTH ||
		    brush->proximity_falloff == MOD_DPAINT_PRFALL_RAMP)
		{
			strength = 1.0f - distance / brush_radius;
			CLAMP(strength, 0.0f, 1.0f);
		}
		else {
			strength = 1.0f;
		}

		if (strength >= 0.001f) {
			float paintColor[3] = {0.0f};
			float depth = 0.0f;
			float velocity_val = 0.0f;

			/* material */
			if (brush_usesMaterial(brush, scene)) {
				float alpha_factor = 1.0f;
				float hit_coord[3];
				MVert *mvert = brush->dm->getVertArray(brush->dm);
				/* use dummy coord of first vertex */
				copy_v3_v3(hit_coord, mvert[0].co);
				mul_m4_v3(brushOb->obmat, hit_coord);

				dynamicPaint_doMaterialTex(bMats, paintColor, &alpha_factor, brushOb, bData->realCoord[bData->s_pos[index]].v, hit_coord, 0, brush->dm);
			}

			/* color ramp */
			if (brush->proximity_falloff == MOD_DPAINT_PRFALL_RAMP && do_colorband(brush->paint_ramp, (1.0f - strength), colorband))
				strength = colorband[3];

			if (brush->flags & MOD_DPAINT_USES_VELOCITY) {
				float velocity[3];

				/* substract canvas point velocity */
				if (bData->velocity) {
					sub_v3_v3v3(velocity, brushVel.v, bData->velocity[index].v);
				}
				else {
					copy_v3_v3(velocity, brushVel.v);
				}
				velocity_val = len_v3(velocity);

				/* store brush velocity for smudge */
				if (surface->type == MOD_DPAINT_SURFACE_T_PAINT && 
				    brush->flags & MOD_DPAINT_DO_SMUDGE && bData->brush_velocity)
				{
					copy_v3_v3(&bData->brush_velocity[index * 4], velocity);
					mul_v3_fl(&bData->brush_velocity[index * 4], 1.0f / velocity_val);
					bData->brush_velocity[index * 4 + 3] = velocity_val;
				}
			}

			if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
				if (brush->proximity_falloff == MOD_DPAINT_PRFALL_RAMP &&
				    !(brush->flags & MOD_DPAINT_RAMP_ALPHA))
				{
					paintColor[0] = colorband[0];
					paintColor[1] = colorband[1];
					paintColor[2] = colorband[2];
				}
				else {
					if (!brush_usesMaterial(brush, scene)) {
						paintColor[0] = brush->r;
						paintColor[1] = brush->g;
						paintColor[2] = brush->b;
					}
				}
			}
			else if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE ||
			         surface->type == MOD_DPAINT_SURFACE_T_WAVE)
			{
				/* get displace depth	*/
				float disp_intersect = (1.0f - sqrtf((brush_radius - distance) / brush_radius)) * brush_radius;
				depth = (brush_radius - disp_intersect) / bData->bNormal[index].normal_scale;
				if (depth < 0.0f) depth = 0.0f;
			}
			dynamicPaint_updatePointData(surface, index, brush, paintColor, strength, depth, velocity_val, timescale);
		}
	}

	return 1;
}


/***************************** Dynamic Paint Step / Baking ******************************/

/*
 *	Calculate current frame distances and directions for adjacency data
 */
static void dynamicPaint_prepareAdjacencyData(DynamicPaintSurface *surface, int force_init)
{
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	BakeAdjPoint *bNeighs;
	PaintAdjData *adj_data = sData->adj_data;
	Vec3f *realCoord = bData->realCoord;
	int index;

	if ((!surface_usesAdjDistance(surface) && !force_init) || !sData->adj_data) return;

	if (bData->bNeighs) MEM_freeN(bData->bNeighs);
	bNeighs = bData->bNeighs = MEM_mallocN(sData->adj_data->total_targets * sizeof(struct BakeAdjPoint), "PaintEffectBake");
	if (!bNeighs) return;

#pragma omp parallel for schedule(static)
	for (index = 0; index < sData->total_points; index++) {
		int i;
		int numOfNeighs = adj_data->n_num[index];

		for (i = 0; i < numOfNeighs; i++) {
			int n_index = adj_data->n_index[index] + i;
			int t_index = adj_data->n_target[n_index];

			/* dir vec */
			sub_v3_v3v3(bNeighs[n_index].dir, realCoord[bData->s_pos[t_index]].v, realCoord[bData->s_pos[index]].v);
			/* dist */
			bNeighs[n_index].dist = len_v3(bNeighs[n_index].dir);
			/* normalize dir */
			if (bNeighs[n_index].dist) mul_v3_fl(bNeighs[n_index].dir, 1.0f / bNeighs[n_index].dist);
		}
	}

	/* calculate average values (single thread) */
	bData->average_dist = 0.0f;
	for (index = 0; index < sData->total_points; index++) {
		int i;
		int numOfNeighs = adj_data->n_num[index];

		for (i = 0; i < numOfNeighs; i++) {
			bData->average_dist += (double)bNeighs[adj_data->n_index[index] + i].dist;
		}
	}
	bData->average_dist  /= adj_data->total_targets;
}

/* find two adjacency points (closest_id) and influence (closest_d) to move paint towards when affected by a force  */
static void surface_determineForceTargetPoints(PaintSurfaceData *sData, int index, float force[3], float closest_d[2], int closest_id[2])
{
	BakeAdjPoint *bNeighs = sData->bData->bNeighs;
	int numOfNeighs = sData->adj_data->n_num[index];
	int i;

	closest_id[0] = closest_id[1] = -1;
	closest_d[0] = closest_d[1] = -1.0f;

	/* find closest neigh */
	for (i = 0; i < numOfNeighs; i++) {
		int n_index = sData->adj_data->n_index[index] + i;
		float dir_dot = dot_v3v3(bNeighs[n_index].dir, force);

		if (dir_dot > closest_d[0] && dir_dot > 0.0f) { closest_d[0] = dir_dot; closest_id[0] = n_index; }
	}

	if (closest_d[0] < 0.0f) return;

	/* find second closest neigh */
	for (i = 0; i < numOfNeighs; i++) {
		int n_index = sData->adj_data->n_index[index] + i;
		float dir_dot = dot_v3v3(bNeighs[n_index].dir, force);
		float closest_dot = dot_v3v3(bNeighs[n_index].dir, bNeighs[closest_id[0]].dir);

		if (n_index == closest_id[0]) continue;

		/* only accept neighbor at "other side" of the first one in relation to force dir
		 *  so make sure angle between this and closest neigh is greater than first angle */
		if (dir_dot > closest_d[1] && closest_dot < closest_d[0] && dir_dot > 0.0f) {
			closest_d[1] = dir_dot; closest_id[1] = n_index;
		}
	}

	/* if two valid neighs found, calculate how force effect is divided
	 *  evenly between them (so that d[0]+d[1] = 1.0)*/
	if (closest_id[1] != -1) {
		float force_proj[3];
		float tangent[3];
		float neigh_diff = acosf(dot_v3v3(bNeighs[closest_id[0]].dir, bNeighs[closest_id[1]].dir));
		float force_intersect;
		float temp;

		/* project force vector on the plane determined by these two neighbor points
		 *  and calculate relative force angle from it*/
		cross_v3_v3v3(tangent, bNeighs[closest_id[0]].dir, bNeighs[closest_id[1]].dir);
		normalize_v3(tangent);
		force_intersect = dot_v3v3(force, tangent);
		madd_v3_v3v3fl(force_proj, force, tangent, (-1.0f) * force_intersect);
		normalize_v3(force_proj);

		/* get drip factor based on force dir in relation to angle between those neighbors */
		temp = dot_v3v3(bNeighs[closest_id[0]].dir, force_proj);
		CLAMP(temp, -1.0f, 1.0f); /* float precision might cause values > 1.0f that return infinite */
		closest_d[1] = acosf(temp) / neigh_diff;
		closest_d[0] = 1.0f - closest_d[1];

		/* and multiply depending on how deeply force intersects surface */
		temp = fabsf(force_intersect);
		CLAMP(temp, 0.0f, 1.0f);
		mul_v2_fl(closest_d, acosf(temp) / (float)M_PI_2);
	}
	else {
		/* if only single neighbor, still linearize force intersection effect */
		closest_d[0] = 1.0f - acosf(closest_d[0]) / (float)M_PI_2;
	}
}

static void dynamicPaint_doSmudge(DynamicPaintSurface *surface, DynamicPaintBrushSettings *brush, float timescale)
{
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	BakeAdjPoint *bNeighs = sData->bData->bNeighs;
	int index, steps, step;
	float eff_scale, max_velocity = 0.0f;

	if (!sData->adj_data) return;

	/* find max velocity */
	for (index = 0; index < sData->total_points; index++) {
		float vel = bData->brush_velocity[index * 4 + 3];
		if (vel > max_velocity) max_velocity = vel;
	}

	steps = (int)ceil(max_velocity / bData->average_dist * timescale);
	CLAMP(steps, 0, 12);
	eff_scale = brush->smudge_strength / (float)steps * timescale;

	for (step = 0; step < steps; step++) {

		for (index = 0; index < sData->total_points; index++) {
			int i;
			PaintPoint *pPoint = &((PaintPoint *)sData->type_data)[index];
			float smudge_str = bData->brush_velocity[index * 4 + 3];

			/* force targets */
			int closest_id[2];
			float closest_d[2];

			if (!smudge_str) continue;
			
			/* get force affect points */
			surface_determineForceTargetPoints(sData, index, &bData->brush_velocity[index * 4], closest_d, closest_id);

			/* Apply movement towards those two points */
			for (i = 0; i < 2; i++) {
				int n_index = closest_id[i];
				if (n_index != -1 && closest_d[i] > 0.0f) {
					float dir_dot = closest_d[i], dir_factor;
					float speed_scale = eff_scale * smudge_str / bNeighs[n_index].dist;
					PaintPoint *ePoint = &((PaintPoint *)sData->type_data)[sData->adj_data->n_target[n_index]];

					/* just skip if angle is too extreme */
					if (dir_dot <= 0.0f) continue;

					dir_factor = dir_dot * speed_scale;
					CLAMP_MAX(dir_factor, brush->smudge_strength);

					/* mix new color and alpha */
					mixColors(ePoint->color, ePoint->color[3], pPoint->color, pPoint->color[3], dir_factor);
					ePoint->color[3] = ePoint->color[3] * (1.0f - dir_factor) + pPoint->color[3] * dir_factor;

					/* smudge "wet layer" */
					mixColors(ePoint->e_color, ePoint->e_color[3], pPoint->e_color, pPoint->e_color[3], dir_factor);
					ePoint->e_color[3] = ePoint->e_color[3] * (1.0f - dir_factor) + pPoint->e_color[3] * dir_factor;
					pPoint->wetness *= (1.0f - dir_factor);
				}
			}
		}
	}
}

/*
 *	Prepare data required by effects for current frame.
 *	Returns number of steps required
 */
static int dynamicPaint_prepareEffectStep(DynamicPaintSurface *surface, Scene *scene, Object *ob, float **force, float timescale)
{
	double average_force = 0.0f;
	float shrink_speed = 0.0f, spread_speed = 0.0f;
	float fastest_effect, avg_dist;
	int steps;
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	Vec3f *realCoord = bData->realCoord;
	int index;

	/* Init force data if required */
	if (surface->effect & MOD_DPAINT_EFFECT_DO_DRIP) {
		float vel[3] = {0};
		ListBase *effectors = pdInitEffectors(scene, ob, NULL, surface->effector_weights, true);

		/* allocate memory for force data (dir vector + strength) */
		*force = MEM_mallocN(sData->total_points * 4 * sizeof(float), "PaintEffectForces");

		if (*force) {
#pragma omp parallel for schedule(static)
			for (index = 0; index < sData->total_points; index++) {
				float forc[3] = {0};

				/* apply force fields */
				if (effectors) {
					EffectedPoint epoint;
					pd_point_from_loc(scene, realCoord[bData->s_pos[index]].v, vel, index, &epoint);
					epoint.vel_to_sec = 1.0f;
					pdDoEffectors(effectors, NULL, surface->effector_weights, &epoint, forc, NULL);
				}

				/* if global gravity is enabled, add it too */
				if (scene->physics_settings.flag & PHYS_GLOBAL_GRAVITY)
					/* also divide by 10 to about match default grav
					 *  with default force strength (1.0) */
					madd_v3_v3fl(forc, scene->physics_settings.gravity, 
					             surface->effector_weights->global_gravity * surface->effector_weights->weight[0] / 10.f);

				/* add surface point velocity and acceleration if enabled */
				if (bData->velocity) {
					if (surface->drip_vel)
						madd_v3_v3fl(forc, bData->velocity[index].v, surface->drip_vel * (-1.0f));

					/* acceleration */
					if (bData->prev_velocity && surface->drip_acc) {
						float acc[3];
						copy_v3_v3(acc, bData->velocity[index].v);
						sub_v3_v3(acc, bData->prev_velocity[index].v);
						madd_v3_v3fl(forc, acc, surface->drip_acc * (-1.0f));
					}
				}

				/* force strength */
				(*force)[index * 4 + 3] = len_v3(forc);
				/* normalize and copy */
				if ((*force)[index * 4 + 3]) mul_v3_fl(forc, 1.0f / (*force)[index * 4 + 3]);
				copy_v3_v3(&((*force)[index * 4]), forc);
			}

			/* calculate average values (single thread) */
			for (index = 0; index < sData->total_points; index++) {
				average_force += (*force)[index * 4 + 3];
			}
			average_force /= sData->total_points;
		}
		pdEndEffectors(&effectors);
	}

	/* Get number of required steps using average point distance
	 *  so that just a few ultra close pixels wont up substeps to max */

	/* adjust number of required substep by fastest active effect */
	if (surface->effect & MOD_DPAINT_EFFECT_DO_SPREAD)
		spread_speed = surface->spread_speed;
	if (surface->effect & MOD_DPAINT_EFFECT_DO_SHRINK)
		shrink_speed = surface->shrink_speed;

	fastest_effect = max_fff(spread_speed, shrink_speed, average_force);
	avg_dist = bData->average_dist * CANVAS_REL_SIZE / getSurfaceDimension(sData);

	steps = (int)ceil(1.5f * EFF_MOVEMENT_PER_FRAME * fastest_effect / avg_dist * timescale);
	CLAMP(steps, 1, 20);

	return steps;
}

/**
 *	Processes active effect step.
 */
static void dynamicPaint_doEffectStep(DynamicPaintSurface *surface, float *force, PaintPoint *prevPoint, float timescale, float steps)
{
	PaintSurfaceData *sData = surface->data;
	BakeAdjPoint *bNeighs = sData->bData->bNeighs;
	float distance_scale = getSurfaceDimension(sData) / CANVAS_REL_SIZE;
	int index;
	timescale /= steps;

	if (!sData->adj_data) return;

	/*
	 *	Spread Effect
	 */
	if (surface->effect & MOD_DPAINT_EFFECT_DO_SPREAD) {
		float eff_scale = distance_scale * EFF_MOVEMENT_PER_FRAME * surface->spread_speed * timescale;

		/* Copy current surface to the previous points array to read unmodified values	*/
		memcpy(prevPoint, sData->type_data, sData->total_points * sizeof(struct PaintPoint));

#pragma omp parallel for schedule(static)
		for (index = 0; index < sData->total_points; index++) {
			int i;
			int numOfNeighs = sData->adj_data->n_num[index];
			PaintPoint *pPoint = &((PaintPoint *)sData->type_data)[index];

			/*  Only reads values from the surface copy (prevPoint[]),
			 *	so this one is thread safe */

			/*	Loop through neighboring points	*/
			for (i = 0; i < numOfNeighs; i++) {
				int n_index = sData->adj_data->n_index[index] + i;
				float w_factor;
				PaintPoint *ePoint = &prevPoint[sData->adj_data->n_target[n_index]];
				float speed_scale = (bNeighs[n_index].dist < eff_scale) ? 1.0f : eff_scale / bNeighs[n_index].dist;
				float color_mix = (MIN3(ePoint->wetness, pPoint->wetness, 1.0f)) * 0.25f * surface->color_spread_speed;

				/* do color mixing */
				if (color_mix) mixColors(pPoint->e_color, pPoint->e_color[3], ePoint->e_color, ePoint->e_color[3], color_mix);

				/* Only continue if surrounding point has higher wetness */
				if (ePoint->wetness < pPoint->wetness || ePoint->wetness < MIN_WETNESS) continue;

				w_factor = 1.0f / numOfNeighs * MIN2(ePoint->wetness, 1.0f) * speed_scale;
				CLAMP(w_factor, 0.0f, 1.0f);

				/* mix new wetness and color */
				pPoint->wetness = (1.0f - w_factor) * pPoint->wetness + w_factor * ePoint->wetness;
				pPoint->e_color[3] = mixColors(pPoint->e_color, pPoint->e_color[3], ePoint->e_color, ePoint->e_color[3], w_factor);
			}
		}
	}

	/*
	 *	Shrink Effect
	 */
	if (surface->effect & MOD_DPAINT_EFFECT_DO_SHRINK) {
		float eff_scale = distance_scale * EFF_MOVEMENT_PER_FRAME * surface->shrink_speed * timescale;

		/* Copy current surface to the previous points array to read unmodified values	*/
		memcpy(prevPoint, sData->type_data, sData->total_points * sizeof(struct PaintPoint));

#pragma omp parallel for schedule(static)
		for (index = 0; index < sData->total_points; index++) {
			int i;
			int numOfNeighs = sData->adj_data->n_num[index];
			float totalAlpha = 0.0f;
			PaintPoint *pPoint = &((PaintPoint *)sData->type_data)[index];

			for (i = 0; i < numOfNeighs; i++) {
				int n_index = sData->adj_data->n_index[index] + i;
				float speed_scale = (bNeighs[n_index].dist < eff_scale) ? 1.0f : eff_scale / bNeighs[n_index].dist;
				PaintPoint *ePoint = &prevPoint[sData->adj_data->n_target[n_index]];
				float a_factor, ea_factor, w_factor;

				totalAlpha += ePoint->e_color[3];

				/* Check if neighboring point has lower alpha,
				 *  if so, decrease this point's alpha as well*/
				if (pPoint->color[3] <= 0.0f && pPoint->e_color[3] <= 0.0f && pPoint->wetness <= 0.0f) continue;

				/* decrease factor for dry paint alpha */
				a_factor = (1.0f - ePoint->color[3]) / numOfNeighs * (pPoint->color[3] - ePoint->color[3]) * speed_scale;
				CLAMP_MIN(a_factor, 0.0f);
				/* decrease factor for wet paint alpha */
				ea_factor = (1.0f - ePoint->e_color[3]) / 8 * (pPoint->e_color[3] - ePoint->e_color[3]) * speed_scale;
				CLAMP_MIN(ea_factor, 0.0f);
				/* decrease factor for paint wetness */
				w_factor = (1.0f - ePoint->wetness) / 8 * (pPoint->wetness - ePoint->wetness) * speed_scale;
				CLAMP_MIN(w_factor, 0.0f);

				pPoint->color[3] -= a_factor;
				CLAMP_MIN(pPoint->color[3], 0.0f);
				pPoint->e_color[3] -= ea_factor;
				CLAMP_MIN(pPoint->e_color[3], 0.0f);
				pPoint->wetness -= w_factor;
				CLAMP_MIN(pPoint->wetness, 0.0f);
			}
		}
	}

	/*
	 *	Drip Effect
	 */
	if (surface->effect & MOD_DPAINT_EFFECT_DO_DRIP && force) {
		float eff_scale = distance_scale * EFF_MOVEMENT_PER_FRAME * timescale / 2.0f;
		/* Copy current surface to the previous points array to read unmodified values	*/
		memcpy(prevPoint, sData->type_data, sData->total_points * sizeof(struct PaintPoint));

		for (index = 0; index < sData->total_points; index++) {
			int i;
			PaintPoint *pPoint = &((PaintPoint *)sData->type_data)[index];
			PaintPoint *pPoint_prev = &prevPoint[index];

			int closest_id[2];
			float closest_d[2];

			/* adjust drip speed depending on wetness */
			float w_factor = pPoint_prev->wetness - 0.025f;
			if (w_factor <= 0) continue;
			CLAMP(w_factor, 0.0f, 1.0f);

			/* get force affect points */
			surface_determineForceTargetPoints(sData, index, &force[index * 4], closest_d, closest_id);

			/* Apply movement towards those two points */
			for (i = 0; i < 2; i++) {
				int n_index = closest_id[i];
				if (n_index != -1 && closest_d[i] > 0.0f) {
					float dir_dot = closest_d[i], dir_factor, a_factor;
					float speed_scale = eff_scale * force[index * 4 + 3] / bNeighs[n_index].dist;
					PaintPoint *ePoint = &((PaintPoint *)sData->type_data)[sData->adj_data->n_target[n_index]];
					float e_wet = ePoint->wetness;

					/* just skip if angle is too extreme */
					if (dir_dot <= 0.0f) continue;

					dir_factor = dir_dot * MIN2(speed_scale, 1.0f) * w_factor;
					CLAMP_MAX(dir_factor, 0.5f);

					/* mix new wetness */
					ePoint->wetness += dir_factor;
					CLAMP(ePoint->wetness, 0.0f, MAX_WETNESS);

					/* mix new color */
					a_factor = dir_factor / pPoint_prev->wetness;
					CLAMP(a_factor, 0.0f, 1.0f);
					mixColors(ePoint->e_color, ePoint->e_color[3], pPoint_prev->e_color, pPoint_prev->e_color[3], a_factor);
					/* dripping is supposed to preserve alpha level */
					if (pPoint_prev->e_color[3] > ePoint->e_color[3]) {
						ePoint->e_color[3] += a_factor * pPoint_prev->e_color[3];
						CLAMP_MAX(ePoint->e_color[3], pPoint_prev->e_color[3]);
					}

					/* decrease paint wetness on current point */
					pPoint->wetness -= (ePoint->wetness - e_wet);
					CLAMP(pPoint->wetness, 0.0f, MAX_WETNESS);
				}
			}
		}
	}
}

static void dynamicPaint_doWaveStep(DynamicPaintSurface *surface, float timescale)
{
	PaintSurfaceData *sData = surface->data;
	BakeAdjPoint *bNeighs = sData->bData->bNeighs;
	int index;
	int steps, ss;
	float dt, min_dist, damp_factor;
	float wave_speed = surface->wave_speed;
	float wave_max_slope = (surface->wave_smoothness >= 0.01f) ? (0.5f / surface->wave_smoothness) : 0.0f;
	double average_dist = 0.0f;
	const float canvas_size = getSurfaceDimension(sData);
	float wave_scale = CANVAS_REL_SIZE / canvas_size;

	/* allocate memory */
	PaintWavePoint *prevPoint = MEM_mallocN(sData->total_points * sizeof(PaintWavePoint), "Temp previous points for wave simulation");
	if (!prevPoint) return;

	/* calculate average neigh distance (single thread) */
	for (index = 0; index < sData->total_points; index++) {
		int i;
		int numOfNeighs = sData->adj_data->n_num[index];

		for (i = 0; i < numOfNeighs; i++) {
			average_dist += bNeighs[sData->adj_data->n_index[index] + i].dist;
		}
	}
	average_dist  *= wave_scale / sData->adj_data->total_targets;

	/* determine number of required steps */
	steps = (int)ceil((WAVE_TIME_FAC * timescale * surface->wave_timescale) / (average_dist / wave_speed / 3));
	CLAMP(steps, 1, 20);
	timescale /= steps;

	/* apply simulation values for final timescale */
	dt = WAVE_TIME_FAC * timescale * surface->wave_timescale;
	min_dist = wave_speed * dt * 1.5f;
	damp_factor = pow((1.0f - surface->wave_damping), timescale * surface->wave_timescale);

	for (ss = 0; ss < steps; ss++) {

		/* copy previous frame data */
		memcpy(prevPoint, sData->type_data, sData->total_points * sizeof(PaintWavePoint));

#pragma omp parallel for schedule(static)
		for (index = 0; index < sData->total_points; index++) {
			PaintWavePoint *wPoint = &((PaintWavePoint *)sData->type_data)[index];
			int numOfNeighs = sData->adj_data->n_num[index];
			float force = 0.0f, avg_dist = 0.0f, avg_height = 0.0f, avg_n_height = 0.0f;
			int numOfN = 0, numOfRN = 0;
			int i;

			if (wPoint->state > 0) continue;

			/* calculate force from surrounding points */
			for (i = 0; i < numOfNeighs; i++) {
				int n_index = sData->adj_data->n_index[index] + i;
				float dist = bNeighs[n_index].dist * wave_scale;
				PaintWavePoint *tPoint = &prevPoint[sData->adj_data->n_target[n_index]];

				if (!dist || tPoint->state > 0) continue;
				if (dist < min_dist) dist = min_dist;
				avg_dist += dist;
				numOfN++;

				/* count average height for edge points for open borders */
				if (!(sData->adj_data->flags[sData->adj_data->n_target[n_index]] & ADJ_ON_MESH_EDGE)) {
					avg_n_height += tPoint->height;
					numOfRN++;
				}

				force += (tPoint->height - wPoint->height) / (dist * dist);
				avg_height += tPoint->height;
			}
			avg_dist = (numOfN) ? avg_dist / numOfN : 0.0f;

			if (surface->flags & MOD_DPAINT_WAVE_OPEN_BORDERS &&
			    sData->adj_data->flags[index] & ADJ_ON_MESH_EDGE)
			{
				/* if open borders, apply a fake height to keep waves going on */
				avg_n_height = (numOfRN) ? avg_n_height / numOfRN : 0.0f;
				wPoint->height = (dt * wave_speed * avg_n_height + wPoint->height * avg_dist) / (avg_dist + dt * wave_speed);
			}
			/* else do wave eq */
			else {
				/* add force towards zero height based on average dist */
				if (avg_dist)
					force += (0.0f - wPoint->height) * surface->wave_spring / (avg_dist * avg_dist) / 2.0f;

				/* change point velocity */
				wPoint->velocity += force * dt * wave_speed * wave_speed;
				/* damping */
				wPoint->velocity *= damp_factor;
				/* and new height */
				wPoint->height += wPoint->velocity * dt;

				/* limit wave slope steepness */
				if (wave_max_slope && avg_dist) {
					float max_offset = wave_max_slope * avg_dist;
					float offset = (numOfN) ? (avg_height / numOfN - wPoint->height) : 0.0f;
					if (offset > max_offset) wPoint->height += offset - max_offset;
					if (offset < -max_offset) wPoint->height += offset + max_offset;
				}
			}
		}
	}

	/* reset state */
#pragma omp parallel for schedule(static)
	for (index = 0; index < sData->total_points; index++) {
		PaintWavePoint *wPoint = &((PaintWavePoint *)sData->type_data)[index];
		/* if there wasnt any brush intersection, clear isect height */
		if (wPoint->state == DPAINT_WAVE_NONE) {
			wPoint->brush_isect = 0.0f;
		}
		wPoint->state = DPAINT_WAVE_NONE;
	}

	MEM_freeN(prevPoint);
}

/* Do dissolve and fading effects */
static void dynamicPaint_surfacePreStep(DynamicPaintSurface *surface, float timescale)
{
	PaintSurfaceData *sData = surface->data;
	int index;

#pragma omp parallel for schedule(static)
	for (index = 0; index < sData->total_points; index++) {
		/* Do drying dissolve effects */
		if (surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
			PaintPoint *pPoint = &((PaintPoint *)sData->type_data)[index];
			/* drying */
			if (surface->flags & MOD_DPAINT_USE_DRYING) {
				if (pPoint->wetness >= MIN_WETNESS) {
					int i;
					float dry_ratio, f_color[4];
					float p_wetness = pPoint->wetness;
					value_dissolve(&pPoint->wetness, surface->dry_speed, timescale, (surface->flags & MOD_DPAINT_DRY_LOG));
					if (pPoint->wetness < 0.0f) pPoint->wetness = 0.0f;

					if (pPoint->wetness < surface->color_dry_threshold) {
						dry_ratio = pPoint->wetness / p_wetness;

						/*
						 *	Slowly "shift" paint from wet layer to dry layer as it drys:
						 */
						/* make sure alpha values are within proper range */
						CLAMP(pPoint->color[3], 0.0f, 1.0f);
						CLAMP(pPoint->e_color[3], 0.0f, 1.0f);

						/* get current final blended color of these layers */
						blendColors(pPoint->color, pPoint->color[3], pPoint->e_color, pPoint->e_color[3], f_color);
						/* reduce wet layer alpha by dry factor */
						pPoint->e_color[3] *= dry_ratio;

						/* now calculate new alpha for dry layer that keeps final blended color unchanged */
						pPoint->color[3] = (f_color[3] - pPoint->e_color[3]) / (1.0f - pPoint->e_color[3]);
						/* for each rgb component, calculate a new dry layer color that keeps the final blend color
						 *  with these new alpha values. (wet layer color doesnt change)*/
						if (pPoint->color[3]) {
							for (i = 0; i < 3; i++) {
								pPoint->color[i] = (f_color[i] * f_color[3] - pPoint->e_color[i] * pPoint->e_color[3]) / (pPoint->color[3] * (1.0f - pPoint->e_color[3]));
							}
						}
					}

					pPoint->state = DPAINT_PAINT_WET;
				}
				/* in case of just dryed paint, just mix it to the dry layer and mark it empty */
				else if (pPoint->state > 0) {
					float f_color[4];
					blendColors(pPoint->color, pPoint->color[3], pPoint->e_color, pPoint->e_color[3], f_color);
					copy_v4_v4(pPoint->color, f_color);
					/* clear wet layer */
					pPoint->wetness = 0.0f;
					pPoint->e_color[3] = 0.0f;
					pPoint->state = DPAINT_PAINT_DRY;
				}
			}

			if (surface->flags & MOD_DPAINT_DISSOLVE) {
				value_dissolve(&pPoint->color[3], surface->diss_speed, timescale, (surface->flags & MOD_DPAINT_DISSOLVE_LOG));
				CLAMP_MIN(pPoint->color[3], 0.0f);

				value_dissolve(&pPoint->e_color[3], surface->diss_speed, timescale, (surface->flags & MOD_DPAINT_DISSOLVE_LOG));
				CLAMP_MIN(pPoint->e_color[3], 0.0f);
			}
		}
		/* dissolve for float types */
		else if (surface->flags & MOD_DPAINT_DISSOLVE &&
		         (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE ||
		          surface->type == MOD_DPAINT_SURFACE_T_WEIGHT))
		{

			float *point = &((float *)sData->type_data)[index];
			/* log or linear */
			value_dissolve(point, surface->diss_speed, timescale, (surface->flags & MOD_DPAINT_DISSOLVE_LOG));
			CLAMP_MIN(*point, 0.0f);
		}
	}
}

static int dynamicPaint_surfaceHasMoved(DynamicPaintSurface *surface, Object *ob)
{
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	DerivedMesh *dm = surface->canvas->dm;
	MVert *mvert = dm->getVertArray(dm);

	int numOfVerts = dm->getNumVerts(dm);
	int i;
	int ret = 0;

	if (!bData->prev_verts) return 1;

	/* matrix comparison */
	for (i = 0; i < 4; i++) {
		int j;
		for (j = 0; j < 4; j++)
			if (bData->prev_obmat[i][j] != ob->obmat[i][j]) return 1;
	}

	/* vertices */
#pragma omp parallel for schedule(static)
	for (i = 0; i < numOfVerts; i++) {
		int j;
		for (j = 0; j < 3; j++)
			if (bData->prev_verts[i].co[j] != mvert[i].co[j]) {
				ret = 1;
				break;
			}
	}

	return ret;
}

static int surface_needsVelocityData(DynamicPaintSurface *surface, const Scene *scene)
{
	if (surface->effect & MOD_DPAINT_EFFECT_DO_DRIP)
		return 1;

	if (surface_getBrushFlags(surface, scene) & BRUSH_USES_VELOCITY)
		return 1;

	return 0;
}

static int surface_needsAccelerationData(DynamicPaintSurface *surface)
{
	if (surface->effect & MOD_DPAINT_EFFECT_DO_DRIP)
		return 1;

	return 0;
}

/* Prepare for surface step by creating PaintBakeNormal data */
static int dynamicPaint_generateBakeData(DynamicPaintSurface *surface, const Scene *scene, Object *ob)
{
	PaintSurfaceData *sData = surface->data;
	PaintAdjData *adj_data = sData->adj_data;
	PaintBakeData *bData = sData->bData;
	DerivedMesh *dm = surface->canvas->dm;
	int index, new_bdata = 0;
	int do_velocity_data = surface_needsVelocityData(surface, scene);
	int do_accel_data = surface_needsAccelerationData(surface);

	int canvasNumOfVerts = dm->getNumVerts(dm);
	MVert *mvert = dm->getVertArray(dm);
	Vec3f *canvas_verts;

	if (bData) {
		int surface_moved = dynamicPaint_surfaceHasMoved(surface, ob);

		/* get previous speed for accelertaion */
		if (do_accel_data && bData->prev_velocity && bData->velocity)
			memcpy(bData->prev_velocity, bData->velocity, sData->total_points * sizeof(Vec3f));

		/* reset speed vectors */
		if (do_velocity_data && bData->velocity && (bData->clear || !surface_moved))
			memset(bData->velocity, 0, sData->total_points * sizeof(Vec3f));

		/* if previous data exists and mesh hasn't moved, no need to recalc */
		if (!surface_moved)
			return 1;
	}

	canvas_verts = (struct Vec3f *) MEM_mallocN(canvasNumOfVerts * sizeof(struct Vec3f), "Dynamic Paint transformed canvas verts");
	if (!canvas_verts) return 0;

	/* allocate memory if required */
	if (!bData) {
		sData->bData = bData = (struct PaintBakeData *) MEM_callocN(sizeof(struct PaintBakeData), "Dynamic Paint bake data");
		if (!bData) {
			if (canvas_verts) MEM_freeN(canvas_verts);
			return 0;
		}

		/* Init bdata */
		bData->bNormal = (struct PaintBakeNormal *) MEM_mallocN(sData->total_points * sizeof(struct PaintBakeNormal), "Dynamic Paint step data");
		bData->s_pos = MEM_mallocN(sData->total_points * sizeof(unsigned int), "Dynamic Paint bData s_pos");
		bData->s_num = MEM_mallocN(sData->total_points * sizeof(unsigned int), "Dynamic Paint bData s_num");
		bData->realCoord = (struct Vec3f *) MEM_mallocN(surface_totalSamples(surface) * sizeof(Vec3f), "Dynamic Paint point coords");
		bData->prev_verts = MEM_mallocN(canvasNumOfVerts * sizeof(MVert), "Dynamic Paint bData prev_verts");

		/* if any allocation failed, free everything */
		if (!bData->bNormal || !bData->s_pos || !bData->s_num || !bData->realCoord || !canvas_verts) {
			if (bData->bNormal) MEM_freeN(bData->bNormal);
			if (bData->s_pos) MEM_freeN(bData->s_pos);
			if (bData->s_num) MEM_freeN(bData->s_num);
			if (bData->realCoord) MEM_freeN(bData->realCoord);
			if (canvas_verts) MEM_freeN(canvas_verts);

			return setError(surface->canvas, N_("Not enough free memory"));
		}

		new_bdata = 1;
	}

	if (do_velocity_data && !bData->velocity) {
		bData->velocity = (struct Vec3f *) MEM_callocN(sData->total_points * sizeof(Vec3f), "Dynamic Paint velocity");
	}
	if (do_accel_data && !bData->prev_velocity) {
		bData->prev_velocity = (struct Vec3f *) MEM_mallocN(sData->total_points * sizeof(Vec3f), "Dynamic Paint prev velocity");
		/* copy previous vel */
		if (bData->prev_velocity && bData->velocity)
			memcpy(bData->prev_velocity, bData->velocity, sData->total_points * sizeof(Vec3f));
	}

	/*
	 *	Make a transformed copy of canvas derived mesh vertices to avoid recalculation.
	 */
	bData->mesh_bounds.valid = 0;
	for (index = 0; index < canvasNumOfVerts; index++) {
		copy_v3_v3(canvas_verts[index].v, mvert[index].co);
		mul_m4_v3(ob->obmat, canvas_verts[index].v);
		boundInsert(&bData->mesh_bounds, canvas_verts[index].v);
	}

	/*
	 *	Prepare each surface point for a new step
	 */
#pragma omp parallel for schedule(static)
	for (index = 0; index < sData->total_points; index++) {
		float prev_point[3] = {0.0f, 0.0f, 0.0f};
		if (do_velocity_data && !new_bdata) {
			copy_v3_v3(prev_point, bData->realCoord[bData->s_pos[index]].v);
		}
		/*
		 *	Calculate current 3D-position and normal of each surface point
		 */
		if (surface->format == MOD_DPAINT_SURFACE_F_IMAGESEQ) {
			float n1[3], n2[3], n3[3];
			ImgSeqFormatData *f_data = (ImgSeqFormatData *)sData->format_data;
			PaintUVPoint *tPoint = &((PaintUVPoint *)f_data->uv_p)[index];
			int ss;

			bData->s_num[index] = (surface->flags & MOD_DPAINT_ANTIALIAS) ? 5 : 1;
			bData->s_pos[index] = index * bData->s_num[index];

			/* per sample coordinates */
			for (ss = 0; ss < bData->s_num[index]; ss++) {
				interp_v3_v3v3v3(bData->realCoord[bData->s_pos[index] + ss].v,
				                 canvas_verts[tPoint->v1].v,
				                 canvas_verts[tPoint->v2].v,
				                 canvas_verts[tPoint->v3].v,
				                 f_data->barycentricWeights[index * bData->s_num[index] + ss].v);
			}

			/* Calculate current pixel surface normal	*/
			normal_short_to_float_v3(n1, mvert[tPoint->v1].no);
			normal_short_to_float_v3(n2, mvert[tPoint->v2].no);
			normal_short_to_float_v3(n3, mvert[tPoint->v3].no);

			interp_v3_v3v3v3(bData->bNormal[index].invNorm,
			                 n1, n2, n3, f_data->barycentricWeights[index * bData->s_num[index]].v);
			mul_mat3_m4_v3(ob->obmat, bData->bNormal[index].invNorm);
			normalize_v3(bData->bNormal[index].invNorm);
			negate_v3(bData->bNormal[index].invNorm);
		}
		else if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
			int ss;
			if (surface->flags & MOD_DPAINT_ANTIALIAS && adj_data) {
				bData->s_num[index] = adj_data->n_num[index] + 1;
				bData->s_pos[index] = adj_data->n_index[index] + index;
			}
			else {
				bData->s_num[index] = 1;
				bData->s_pos[index] = index;
			}

			/* calculate position for each sample */
			for (ss = 0; ss < bData->s_num[index]; ss++) {
				/* first sample is always point center */
				copy_v3_v3(bData->realCoord[bData->s_pos[index] + ss].v, canvas_verts[index].v);
				if (ss > 0) {
					int t_index = adj_data->n_index[index] + (ss - 1);
					/* get vertex position at 1/3 of each neigh edge */
					mul_v3_fl(bData->realCoord[bData->s_pos[index] + ss].v, 2.0f / 3.0f);
					madd_v3_v3fl(bData->realCoord[bData->s_pos[index] + ss].v, canvas_verts[adj_data->n_target[t_index]].v, 1.0f / 3.0f);
				}
			}

			/* normal */
			normal_short_to_float_v3(bData->bNormal[index].invNorm, mvert[index].no);
			mul_mat3_m4_v3(ob->obmat, bData->bNormal[index].invNorm);
			normalize_v3(bData->bNormal[index].invNorm);
			negate_v3(bData->bNormal[index].invNorm);
		}

		/* Prepare surface normal directional scale to easily convert
		 *  brush intersection amount between global and local space */
		if (surface->type == MOD_DPAINT_SURFACE_T_DISPLACE ||
		    surface->type == MOD_DPAINT_SURFACE_T_WAVE)
		{
			float temp_nor[3];
			if (surface->format == MOD_DPAINT_SURFACE_F_VERTEX) {
				normal_short_to_float_v3(temp_nor, mvert[index].no);
				normalize_v3(temp_nor);
			}
			else {
				float n1[3], n2[3], n3[3];
				ImgSeqFormatData *f_data = (ImgSeqFormatData *)sData->format_data;
				PaintUVPoint *tPoint = &((PaintUVPoint *)f_data->uv_p)[index];

				normal_short_to_float_v3(n1, mvert[tPoint->v1].no);
				normal_short_to_float_v3(n2, mvert[tPoint->v2].no);
				normal_short_to_float_v3(n3, mvert[tPoint->v3].no);
				interp_v3_v3v3v3(temp_nor,
				                 n1, n2, n3, f_data->barycentricWeights[index * bData->s_num[index]].v);
			}

			mul_v3_v3(temp_nor, ob->size);
			bData->bNormal[index].normal_scale = len_v3(temp_nor);
		}

		/* calculate speed vector */
		if (do_velocity_data && !new_bdata && !bData->clear) {
			sub_v3_v3v3(bData->velocity[index].v, bData->realCoord[bData->s_pos[index]].v, prev_point);
		}
	}

	MEM_freeN(canvas_verts);

	/* generate surface space partitioning grid */
	surfaceGenerateGrid(surface);
	/* calculate current frame adjacency point distances and global dirs */
	dynamicPaint_prepareAdjacencyData(surface, 0);

	/* Copy current frame vertices to check against in next frame */
	copy_m4_m4(bData->prev_obmat, ob->obmat);
	memcpy(bData->prev_verts, mvert, canvasNumOfVerts * sizeof(MVert));

	bData->clear = 0;

	return 1;
}

/*
 * Do Dynamic Paint step. Paints scene brush objects of current state/frame to the surface.
 */
static int dynamicPaint_doStep(Scene *scene, Object *ob, DynamicPaintSurface *surface, float timescale, float subframe)
{
	PaintSurfaceData *sData = surface->data;
	PaintBakeData *bData = sData->bData;
	DynamicPaintCanvasSettings *canvas = surface->canvas;
	int ret = 1;
	if (sData->total_points < 1) return 0;

	dynamicPaint_surfacePreStep(surface, timescale);
	/*
	 * Loop through surface's target paint objects and do painting
	 */
	{
		Base *base = NULL;
		GroupObject *go = NULL;
		Object *brushObj = NULL;
		ModifierData *md = NULL;

		/* backup current scene frame */
		int scene_frame = scene->r.cfra;
		float scene_subframe = scene->r.subframe;

		/* either from group or from all objects */
		if (surface->brush_group)
			go = surface->brush_group->gobject.first;
		else
			base = scene->base.first;

		while (base || go) {
			brushObj = NULL;
			/* select object */
			if (surface->brush_group) {
				if (go->ob) brushObj = go->ob;
			}
			else
				brushObj = base->object;

			if (!brushObj) {
				/* skip item */
				if (surface->brush_group) go = go->next;
				else base = base->next;
				continue;
			}

			/* next item */
			if (surface->brush_group)
				go = go->next;
			else
				base = base->next;

			/* check if target has an active dp modifier	*/
			md = modifiers_findByType(brushObj, eModifierType_DynamicPaint);
			if (md && md->mode & (eModifierMode_Realtime | eModifierMode_Render)) {
				DynamicPaintModifierData *pmd2 = (DynamicPaintModifierData *)md;
				/* make sure we're dealing with a brush	*/
				if (pmd2->brush) {
					DynamicPaintBrushSettings *brush = pmd2->brush;
					BrushMaterials bMats = {NULL};

					/* calculate brush speed vectors if required */
					if (surface->type == MOD_DPAINT_SURFACE_T_PAINT && brush->flags & MOD_DPAINT_DO_SMUDGE) {
						bData->brush_velocity = MEM_callocN(sData->total_points * sizeof(float) * 4, "Dynamic Paint brush velocity");
						/* init adjacency data if not already */
						if (!sData->adj_data)
							dynamicPaint_initAdjacencyData(surface, 1);
						if (!bData->bNeighs)
							dynamicPaint_prepareAdjacencyData(surface, 1);
					}

					/* update object data on this subframe */
					if (subframe) {
						scene_setSubframe(scene, subframe);
						subframe_updateObject(scene, brushObj, UPDATE_EVERYTHING, SUBFRAME_RECURSION, BKE_scene_frame_get(scene));
					}
					/* Prepare materials if required	*/
					if (brush_usesMaterial(brush, scene))
						dynamicPaint_updateBrushMaterials(brushObj, brush->mat, scene, &bMats);

					/* Apply brush on the surface depending on it's collision type */
					/* Particle brush: */
					if (brush->collision == MOD_DPAINT_COL_PSYS) {
						if (brush->psys && brush->psys->part && ELEM(brush->psys->part->type, PART_EMITTER, PART_FLUID) &&
						    psys_check_enabled(brushObj, brush->psys))
						{

							/* Paint a particle system */
							BKE_animsys_evaluate_animdata(scene, &brush->psys->part->id, brush->psys->part->adt, BKE_scene_frame_get(scene), ADT_RECALC_ANIM);
							dynamicPaint_paintParticles(surface, brush->psys, brush, timescale);
						}
					}
					/* Object center distance: */
					else if (brush->collision == MOD_DPAINT_COL_POINT && brushObj != ob) {
						dynamicPaint_paintSinglePoint(surface, brushObj->loc, brush, brushObj, &bMats, scene, timescale);
					}
					/* Mesh volume/proximity: */
					else if (brushObj != ob) {
						dynamicPaint_paintMesh(surface, brush, brushObj, &bMats, scene, timescale);
					}

					/* free temp material data */
					if (brush_usesMaterial(brush, scene))
						dynamicPaint_freeBrushMaterials(&bMats);
					/* reset object to it's original state */
					if (subframe) {
						scene->r.cfra = scene_frame;
						scene->r.subframe = scene_subframe;
						subframe_updateObject(scene, brushObj, UPDATE_EVERYTHING, SUBFRAME_RECURSION, BKE_scene_frame_get(scene));
					}

					/* process special brush effects, like smudge */
					if (bData->brush_velocity) {
						if (surface->type == MOD_DPAINT_SURFACE_T_PAINT && brush->flags & MOD_DPAINT_DO_SMUDGE)
							dynamicPaint_doSmudge(surface, brush, timescale);
						MEM_freeN(bData->brush_velocity);
						bData->brush_velocity = NULL;
					}
				}
			}
		}
	}

	/* surfaces operations that use adjacency data */
	if (sData->adj_data && bData->bNeighs) {
		/* wave type surface simulation step */
		if (surface->type == MOD_DPAINT_SURFACE_T_WAVE) {
			dynamicPaint_doWaveStep(surface, timescale);
		}

		/* paint surface effects */
		if (surface->effect && surface->type == MOD_DPAINT_SURFACE_T_PAINT) {
			int steps = 1, s;
			PaintPoint *prevPoint;
			float *force = NULL;

			/* Allocate memory for surface previous points to read unchanged values from	*/
			prevPoint = MEM_mallocN(sData->total_points * sizeof(struct PaintPoint), "PaintSurfaceDataCopy");
			if (!prevPoint)
				return setError(canvas, N_("Not enough free memory"));

			/* Prepare effects and get number of required steps */
			steps = dynamicPaint_prepareEffectStep(surface, scene, ob, &force, timescale);
			for (s = 0; s < steps; s++) {
				dynamicPaint_doEffectStep(surface, force, prevPoint, timescale, (float)steps);
			}

			/* Free temporary effect data	*/
			if (prevPoint) MEM_freeN(prevPoint);
			if (force) MEM_freeN(force);
		}
	}

	return ret;
}

/*
 * Calculate a single frame and included subframes for surface
 */
int dynamicPaint_calculateFrame(DynamicPaintSurface *surface, Scene *scene, Object *cObject, int frame)
{
	float timescale = 1.0f;

	/* apply previous displace on derivedmesh if incremental surface */
	if (surface->flags & MOD_DPAINT_DISP_INCREMENTAL)
		dynamicPaint_applySurfaceDisplace(surface, surface->canvas->dm);

	/* update bake data */
	dynamicPaint_generateBakeData(surface, scene, cObject); 
	
	/* don't do substeps for first frame */
	if (surface->substeps && (frame != surface->start_frame)) {
		int st;
		timescale = 1.0f / (surface->substeps + 1);

		for (st = 1; st <= surface->substeps; st++) {
			float subframe = ((float) st) / (surface->substeps + 1);
			if (!dynamicPaint_doStep(scene, cObject, surface, timescale, subframe)) return 0;
		}
	}

	return dynamicPaint_doStep(scene, cObject, surface, timescale, 0.0f);
}
