Hot answers tagged textures
If the textures are the same general "shape" (dimensions, mip levels, etc.) then use texture arrays. You can pack differently "shaped" textures into different arrays if you have any regularity, which you should. This approach gives you all the advantages of individual textures (e.g., no bleeding) plus all the advantages of a texture atlas (e.g. fewer state ...
Unity is pretty smart about keeping stuff around that you need in the future. What's more difficult is telling it when to get rid of stuff you don't need anymore. So yes, once this texture is loaded, it will recognize that and not load it again provided something hasn't removed it from memory in the meantime.
So the short answer to my own question is, "Yes." The long answer is... Using Metal—and, I assume, OpenGL ES—you can create no-copy data buffers from memory-mapped files on disk. From there, you can create textures from those buffers. There are constraints, however, in that the texture data must be an uncompressed pixel format, can only have one mipmap ...
Only top voted, non community-wiki answers of a minimum length are eligible