I was trying to make a custom Unwrap but was not cutting along the selection. It looks buggy. And I was not able to make individual custom unwrapping for a polysurface (or I do not know how to use multiple mapping channels). So the object was divided it into 3 different polysurface and apply different mapping technic to each one. But when I use “join” I lose its individual texture mapping unwrap.
I wish an option in “join” that allows preserving the texture mapping and (automatically) assign each one to different channels in the final polysurface. This option can save me some time and can be simple to understand for how do not understand how to configure and use texture mapping channels.
NOTE: In-game dev and VR presentation we need to limit the draw calls. So we need a joined mesh.