Standard meta data keys

Standard Ptex keys are documented in the following table.

Key	Type	Description	Count
PtexFaceVertCounts	int32	Number of vertices for each face.	one value per face
PtexFaceVertIndices	int32	Index of each face vert within PtexVertPositions array.	one value per vertex per face
PtexVertPositions	float	3d position of each vertex.	three values per vertex

The PtexFaceVertCounts, PtexFaceVertIndices, and PtexVertPositions can be used to describe geometry on which the Ptex texture can be mapped. This data isn't used directly by the Ptex library but can be used by 3d painting programs, Ptex texture viewers, or similar applications.

Notes:

• The faceids and per-face UVs used to map the Ptex texture data are implied by the face and vertex ordering listed in these keys.
• Non-quad faces are allowed. They are not required to be subdivided into quad subfaces as with the texture data. Thus, the faceids in the texture data may not match the entries in the meta data exactly, though they will be in the same order.