Namely Height, UV and index. Does anyone know how to do it properly ? Or at least on what principles? Bits masking or something maybe? I am trying to do it for FX map in 32 bit mode. Something similar to what available for shape splatter in which pixel processors I couldn't understand a thing so it looks easier to invent…
It looks like the error is coming from your normals map. The stepped gradient is that purple area light purple area on the door. Also, don't use 32-bit TGA for your normals map. You only use 32-bit when you have an alpha mask. Normals don't need an alpha channel. Go with 24-bit and don't compress anything.