playcanvas / playcanvas/engine
Investigate using LUTs instead of calculating sheen weights in shader
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- Dominant language
- JavaScript
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Description
Description
PR #4460 adds sheen to the standard material. The glTF reference implementation uses two LUTs for the BRDFs, one to weight the underlying layers, and one to weight the reflections. Currently, the weight used to blend the layers is a constant value, which is fine, but the weight used for the environment reflections is more costly, as it's currently done in an analytical manner.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reviewing PR #4460 and the standard material's sheen shader changes, then compare them with the glTF reference implementation's two BRDF LUTs. Determine whether the environment-reflection weight can use a LUT instead of its analytical calculation, and validate that the sheen layering and reflections still match the reference behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- computer-graphics, performance
- Issue type
- Refactor
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 30/100