somebody could correct me if I am wrong because I dont do a ton of this sort of thing but I think it is correct to say that a trim sheet is a texture atlas, the only thing which makes it different is the intent it's used for. So if you combine the textures of ten characters into one image, thats a texture atlas. If you…
If a trimsheet doesn't allow for wrapping outside of 0-1, it's no longer a trim sheet and just an atlas, at least in my opinion. You can use unused space on a trimsheet as an atlas though.
You can mix trim sheets with unique normal maps. I do it all the time. On all these props there is still a lot of texture re-use. If you look at the window frames they use the same wooden pieces over and over again but in different configurations. This is just another way to save on texture resolution.
Building modules from a set amount of parts means their UVs are mapped to same pixels, maximizing the use of the texture - same as with mapping UVs of several parts to trims. As poopie wrote, it's fine to combine unique and tiling elements into one texture. Approach depends on the specific kit. What matters in the end is…
This thread seems to be running in circles, perhaps because of a misunderstanding of the question by the OP - and then things get even more mixed up because of terminology. @Elliott : you seem to understand the difference between "unique" UVs (say, for a typical character) and "environment style" UVs. Why do you assume…