Are there any plans to support BC6H for lightmap textures? I have a quality issue that’s caused by the RGBM compression used in lightmaps (as far as I can tell), and being able to use BC6H for them would produce far superior results for the same amount of texture memory and slightly lower ALU usage. Texture filtering cost would be higher of course, but the quality improvement is definitely worth that tradeoff in my case.
Here is the results of a lightmap produced by two lights with intensity of 8.0 in the default scene, with DXT5 compression on the lightmap:
And with BC7 compression - better, but still not great:
And finally still BC7 compression but with the ‘Texture type’ changed from ‘Lightmap’ to ‘Default’ so it doesn’t do any RGBM compression:
This is the same size in memory and more or less free of artifacts, but is obviously going have problems with clipping and color shifting once the values get too bright, and isn’t a general solution.
This problem is potentially much worse in Unity 5.6, now that light intensities aren’t clamped to 8; a light of intensity 32 produces really bad compression artifacts even with BC7:
While I wouldn’t expect BC6H to be completely free from compression artifacts, I would expect it to produce much better quality than RGBM.
Are there any plans to implement this?
