Description

I think we should offer AgX as a tone mapper in three.js. It has better fundamentals than others like Reinhardt or ACES¹, often provides a more natural appearance, and — importantly — is the new default in Blender 4.0. Supporting AgX would make consistent color across Blender and three.js much easier for users.

Additionally, I feel more comfortable using AgX in wide-gamut workflows (see #26479).

Solution

AgX has been discussed in a few other threads previously:

• Roadmap for supporting wide-gamut color workflows #26479 (comment)
• Pluggable Tone Mapping Operators (their own class that injects GLSL) #26661 (comment)

While I've done some proof-of-concept implementations myself, none are ready for production. Notably, we'd want to replace the LUTs with a piecewise-linear function (or similar), and perhaps to support the "golden" and "punchy" looks.

The Filament implementation is probably a good reference here.

Alternatives

• "Filmic": Previous Blender default. AgX improves on this, and I'm not sure there's any particular reason to go back to Filmic.
• "Commerce": Available in model-viewer, and has starts from somewhat different goals than AgX. I believe AgX is probably the place we should start, but Commerce could be a worthwhile addition later.

Additional context

No response