I know umodel doesn't attempt to recreate complex materials - does a MATINST count as a complex material?
umodel has MaterialInstanceConstant support.
The typical diffuse, specular and normal map textures *are* in the uppc, but most of them are the low-res "thumbnail" used in streaming. There are *some* diffuse/specular/normal textures that appear normal, but they are never larger than 256x256. This is slightly different to how coalesced.tfc works in later version of the UE3, but R6V2 was a very early UE3 game.
Yes, TFC files appeared much later in UE3.
The log file reports a lot of "WARNING: ByteProperty "UTexture2D::TextureType" was not found" when opening a package.
This message means nothing.
I haven't been able to locate the hi-res textures - hence why I thought they could be in the .RMPC, .shaders, or the .usdx files.
Sorry, I have no this game so I cannot test this by myself.