Hello.
Which one is better for iOS →
using 20 of the 2048x2048 texture and 20 material or using 40 of the 1024x1024 texture and 40 material.
thx.
Well the difference between 1024x1024 and 2048x2048 is a power of two. So not sure why your material count only doubles, shouldn’t it quadruple?
If you simply compare the memory required for textures:
1x 2048x2048 @ Truecolor = 16 MB
20x 2048x2048 @ Truecolor = 320 MB
1x 1024x1024 @ Truecolor = 4 MB
40x 1024x1024 @ Truecolor = 160 MB
From a memory point of view, 40x textures at 1024 would be better option. It’s half the memory required.
Now, in case you messed up the material count and actually meant 160x textures sized at 1024, the memory required would be the same (320 MB). I’m not sure which would be the better option here, I don’t like either, as they both seem excessive. But to answer the question, I guess using the smaller textures would be better, because then if an object is being culled then it’s texture won’t have to be drawn. If you have objects using a larger texture as an atlas, then the entire atlas will need to be drawn even if one object only uses a portion of the atlas.
Then again the answer depends on the application, maybe all textures are always present and you want to perform batching, then using the larger textures might be better.