# I author a splat prim in USD: should I set sortingModeHint and projectionModeHint, and will Hydra renderers honour them at v26.11.0?

- id: art_01M5ME6BJEKFPX1Y9MP1H7C6B7
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T15, T19 · tags: none
- updated: 2026-10-23T13:11:21.402Z
- url: https://veyrul.com/articles/art_01M5ME6BJEKFPX1Y9MP1H7C6B7

The hints are advisory: at v26.11.0 they reach Hydra scene data, but Pixar's inspected consumers (hdPrman conversion, sample renderer) do not read them, so setting them is harmless and should not be expected to change output there; the docs now describe rayHitDistance and say rasterizers may treat it as cameraDistance.

The hints are advisory: at v26.11.0 they reach Hydra scene data, but Pixar's inspected consumers (hdPrman conversion, sample renderer) do not read them, so setting them is harmless and should not be expected to change output there; the docs now describe rayHitDistance and say rasterizers may treat it as cameraDistance.

Curator qualifications: Code read at three tags 2026-10-22; not built or run (code reading, not execution).

Limitations: Code read at three tags 2026-10-22; not built or run (code reading, not execution).

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://github.com/PixarAnimationStudios/OpenUSD/blob/5b3c21a1f20a77383fd6e7814ce6bde4e6c1895d/pxr/usdImaging/usdVolImaging/dataSourceParticleField.cpp",
      "note": "docs ParticleField3DGaussianSplat.md at v26.11.0, L39-83; hdPrman particleFieldConversionSceneIndexPlugin.cpp at v26.11.0"
    },
    {
      "url": "https://github.com/PixarAnimationStudios/OpenUSD/blob/5b3c21a1f20a77383fd6e7814ce6bde4e6c1895d/pxr/imaging/hd/particleFieldSchema.h",
      "note": "docs ParticleField3DGaussianSplat.md at v26.11.0, L39-83; hdPrman particleFieldConversionSceneIndexPlugin.cpp at v26.11.0"
    },
    {
      "url": "https://github.com/PixarAnimationStudios/OpenUSD/blob/5b3c21a1f20a77383fd6e7814ce6bde4e6c1895d/third_party/renderman/plugin/hdPrman/particleFieldConversionSceneIndexPlugin.cpp",
      "note": "docs ParticleField3DGaussianSplat.md at v26.11.0, L39-83; hdPrman particleFieldConversionSceneIndexPlugin.cpp at v26.11.0"
    },
    {
      "url": "https://github.com/PixarAnimationStudios/OpenUSD/blob/5b3c21a1f20a77383fd6e7814ce6bde4e6c1895d/docs/user_guides/schemas/usdVol/ParticleField3DGaussianSplat.md",
      "note": "docs ParticleField3DGaussianSplat.md at v26.11.0, L39-83; hdPrman particleFieldConversionSceneIndexPlugin.cpp at v26.11.0"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] The hints are advisory: at v26.11.0 they reach Hydra scene data, but Pixar's inspected consumers (hdPrman conversion, sample renderer) do not read them, so setting them is harmless and should not be expected to change output there; the docs now describe rayHitDistance and say rasterizers may treat it as cameraDistance. · locator: docs ParticleField3DGaussianSplat.md at v26.11.0, L39-83; hdPrman particleFieldConversionSceneIndexPlugin.cpp at v26.11.0 · source: https://github.com/PixarAnimationStudios/OpenUSD/blob/5b3c21a1f20a77383fd6e7814ce6bde4e6c1895d/pxr/usdImaging/usdVolImaging/dataSourceParticleField.cpp

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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