Just wondering how people deal with alpha and texture atlases? I have a bunch of straight diffuse textures and some with alpha. Is it best to separate them into two atlases? Or the diffuse info of ALL textures in one sheet, and a second sheet with just greyscale for alpha info?
This sounds like a workflow/performance trade off which may also depend on your target platform. It can be beneficial to separate these as then any sprites without alpha can be cheaper to render using a simple diffuse than say an alpha blended or cutout shader. However if performance isn’t a consideration then your workflow may be simpler to not separate. Your best bet would be to profile on your target platform the different options.
Yah the ones with alpha would need 2 texture lookups, vs one, which will be slower, but the ones without will be faster due to less bytes being read… so its a matter of whether you have more fill rate used by non-alpha vs the ones with alpha. If they’re about the same, then it may not be worth it.
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