I have a set of textures which are compressing as DXT5 (RGBA)... but all I need is the Alpha. A lot of space would be saved by finding a way to store these textures with as single channel or at least DXT1, and coax Unity to use the grayscale as Alpha.
I need this for a GUI which uses a few large textures. The textures are pure white with lots of detail in their transparency channel. I use the GUI.color to set the desired color of each texture as I render it with GUI.DrawTexture.
I cannot find a way to use GUI.DrawTexture with a black and white DXT1 to achieve a blended effect. Is this possible?