I find that our PBR maps as they are right now have 2 problems, please let's discuss this while there are still extremely few PBR ships, and before it is to late and everything is set in stone :
1: For most of our ships, the "most important" map is going to be the -reflect map, as many spaceships are going to be a big part made out of metal, this is the map that is going to be the most "visible" in many cases + it holds the roughness information; BUT it's also going to be the one with the most .dds compression errors
it is the only map using 4 channels, 3 for color, 1 for roughness; This is very bad because of compression artefacts, maps with only 2 or 3 channels being used produce MUCH better results in my experience!
hence the following suggestion:
move the roughness somewhere else, my suggestion would be the blue channel of the AO map
advantages:
- less compression artefacts in the relfection map!
- roughness ALSO is going to have less artifacts
- reflection map can be compressed without alpha channel -> saving memory, more than 1/2 of the texture actually!
- ao map can still be compressed without alpha channel -> memory for ao does not increase -> net gain of memory!
- it is more intuative to work with the reflection map, as not the whole damn thing is transparent as soon as it has some roughness
disadvantages:
- slightly less intuative AO map; Roughness in AO, hugh? mostly just a problem the very first time however
- slightly more compression artefacts in the AO, but here they matter the least by far, they are going to be the least visible here!
2. normal maps using the green/alpha channel, instead of the traditional red and green. there are several reasons to not do this anymore, if we are changing the renderer anyway:
advantages:
- no more alpha channel needed in normal maps -> saving memory, again only half the size!
- normal maps are easier to create, less steps needed than to convert from red/green/blue to green/alpha
- it's more intuative, almost every other application out there uses these channels
disadvantages:
- legacy support, but this should be simple: if there is a -albedo map, read the old channels, otherwise, the new ones! something like this has to be in place already to read the old -spec maps anyway
overall i just don't see any valid reason not to make these changes, as long as we still can, the memory saving aspect alone should be enough for a start, and the ships are only going to look better for it!
i hope i didn't forget anything important