SPIR-V Built-In

TessCoord

Barycentric coordinate of a tessellated vertex within a patch
TessCoord

Decorating a variable with the TessCoord built-in decoration will make that variable contain the three-dimensional (u,v,w) barycentric coordinate of the tessellated vertex within the patch. u, v, and w are in the range [0,1] and vary linearly across the primitive being subdivided. For the tessellation modes of Quads or IsoLines, the third component is always zero.

Valid Usage

VUID-TessCoord-TessCoord-04387

The TessCoord decoration must be used only within the TessellationEvaluation Execution Model

VUID-TessCoord-TessCoord-04388

The variable decorated with TessCoord must be declared using the Input Storage Class

VUID-TessCoord-TessCoord-04389

The variable decorated with TessCoord must be declared as a three-component vector of 32-bit floating-point values