Ok, this has probs been asked before, and I know the uses of it are moderately limited to special effects, but I was thinking that it would be nice to have a texturename-t.pcx which is a greyscale (or lower) image, the lighter the colour, the more opaque the texture. This would, at first thought, go a long way towards helping people trying to create cloud/nebulae and other effects, as well as being usefull for planetary atmospheres, force fields and other freaky spacey plot-device things?
Of course, to save a lot of memory, if there is no -t texture, it could just process the texture as normal, alpha greens and all.
Flipside
