From this vid on photogammentry, https://www.youtube.com/watch?v=U_WaqCBp9zo RGBA was used for the detailed textures, RG for Normal, B for roughness, A for Color. From here, someone wrote:https://answers.unrealengine.com/questions/699690/is-it-possible-to-use-all-4-channels-rgba-in-textu.html ''yes, you can use all 4…