Memoryless textures are only used as intermediate attachments during rasterization, but do not have any backing storage. This is particularly useful if a virutal framebuffer is needed, or, there is a situation where a depth buffer is only needed within the pass itself and the results are discarded once the pass completes. Authored by Apple: Michael Parkin-White Pull Request: https://projects.blender.org/blender/blender/pulls/111749