WebGLTextures: Only use anistropic filtering with certain minFilter/magFilter combinations.

[hybridherbst]

Fixed #25067

Description

Fixes the above mentioned issue by not setting anisotropy if the texture has NEAREST magFilter.

I'm not sure: would this need to be applied on the new WebGPURenderer and so on as well?

This contribution is funded by Needle

[Mugen87]

Although it's technically possible I've thought you should always use anistropic filtering with mipmapping for performance reasons (see https://paroj.github.io/gltut/Texturing/Tut15%20Anisotropy.html). So we could also check for ( texture.minFilter !== NearestFilter && texture.minFilter !== LinearFilter ).

[hybridherbst]

Makes sense. I hope I get to change this next week.

[elalish]

Good catch! I think I'll wait on google/model-viewer#4005 until this fix is in. If it can sneak into r148, that would be much appreciated!

[hybridherbst]

I believe I got all cases right now; I compared behaviour with aniso=1 and =4 for a number of combinations of minFilter and magFilter (including some weird ones).

• magFilter === Nearest must be excluded
• only minFilter === NearestMipmapLinearFilter and minFilter === LinearMipmapLinearFilter are the remaining options where anisotropy makes sense

Test file:
TextureFiltering-Pixelgraphics.zip