GeometryIndex

Description

Returns the index of the geometry that was hit in an intersection, any-hit, or closest-hit shader.

Signature

uint GeometryIndex();

Return value

Zero-based index of the geometry in the current instance. On CUDA/OptiX, the SBT GAS index of the hit primitive, which equals the geometry index when every build input of the geometry acceleration structure has one shader binding table record (see “Geometry index” in the CUDA target documentation).

Remarks

Available in intersection, any-hit, and closest-hit shaders

Availability and Requirements

Defined for the following targets:

hlsl

Available in stages: intersection, closesthit, anyhit.

glsl

Available in stages: intersection, closesthit, anyhit.

cuda

Available in stages: intersection, closesthit, anyhit.

spirv

Available in stages: intersection, closesthit, anyhit.

Requires capability: spvRayTracingKHR.