Joining Two Different Meshes Destroys UVs of another [HELP]

I have a group of different chocolate chip cookies with 3 different materials/uvs and I want to join them all as one object.

However whenever I join the meshes some uvs get destroyed, what am i doing wrong?


I guess you are trying to join two (edit: multiple) mesh objects that have a UV Map with the same name. Before joining them, make sure to name them (UV Maps) different from each other… like UVMap1 & UVMap2 … something like that.

so for every mesh i want to join, i have to create unique uv names?
kind of annoying though…

Unless you can be sure each object has an identical UV layout, you’ll always need to move the maps around if they use the same material. If they use different materials, the various parts can have overlapping uv’s without an issue. Even if it’s one mesh, you can overlap uv’s if is suits the result.
The right hand objects share one UVMap and one material, but with the uv’s edited. The left hand side, the uvs are edited and each piece has it’s own material. Joining them together should not destroy the map though, as the uv’s for that bit of geometry will have already been laid out.