#### 4.2.1 QUAD: collection of quadrilaterals

The conventional suffix for a `QUAD` file is `.quad`.

The file syntax is

            [C][N][4]QUAD  -or-  [C][N][4]POLY              # Key word
            vertex  vertex  vertex  vertex  # 4*N vertices for some N
            vertex  vertex  vertex  vertex
            ...

The leading key word is `[C][N][4]QUAD` or `[C][N][4]POLY`, where the optional `C` and `N` prefixes indicate that each vertex includes colors and normals respectively. That is, these files begin with one of the words

`QUAD` `CQUAD` `NQUAD` `CNQUAD` `POLY` `CPOLY` `NPOLY` `CNPOLY`

(but not `NCQUAD` or `NCPOLY`). `QUAD` and `POLY` are synonymous; both forms are allowed just for compatibility with ChapReyes.

Following the key word is an arbitrary number of groups of four vertices, each group describing a quadrilateral. See the Vertex syntax above. The object ends at end-of-file, or with a close-brace if incorporated into an object reference (see above).

A `QUAD BINARY` file format is accepted; See Binary format. The first word of binary data must be a 32-bit integer giving the number of quads in the object; following that is a series of 32-bit floats, arranged just as in the ASCII format.