# HdMeshUtil::ComputeTriangleIndices and the UsdGeomSubset indices attribute

**URL:** <https://forum.aousd.org/t/hdmeshutil-computetriangleindices-and-the-usdgeomsubset-indices-attribute/2504>\
**Category:** Hydra\
**Tags:** rendering, cpp\
**Created:** [June 6, 2025, 4:30am UTC](https://forum.aousd.org/t/hdmeshutil-computetriangleindices-and-the-usdgeomsubset-indices-attribute/2504 "2025-06-06T04:30:19Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![omnnai](https://avatars.discourse-cdn.com/v4/letter/o/c89c15/32.png) [@omnnai](https://forum.aousd.org/u/omnnai)\
**Post date:** [June 6, 2025, 4:30am UTC](https://forum.aousd.org/t/hdmeshutil-computetriangleindices-and-the-usdgeomsubset-indices-attribute/2504/1 "2025-06-06T04:30:19Z")

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I am using Hydra for a typical rasterizer with a Vulkan backend.

I rely on the HdMeshUtil::ComputeTriangleIndices to produce a single index buffer that can be used for reading from various vertex streams.

Some meshes specify multiple material bindings through the UsdGeomSubset concept. The issue is those subsets seem to specify the target indices with respect to the pre-triangulated indices in the asset.

Do I need to manually triangulate the indices specified in the UsdGeomSubset?