Thank you, @theluthier, for your advice. I have already tried to find out what could have “confused” the “Join as UVs” function but couldn’t remember anyhing and some experiments with recalculating the vertex order didn’t work either. The big question is whether I could do something before copying the UV that ensure that the “Join as UVs” function gets good mesh data in order to do its job properly. Are there ways to examine the mesh so that I can see prior to copying the UVs whether the mesh is ready for this UV function? Displaying the vertex indices didn’t give me a clue.
PS:
But when we get into the technical weeds of animation production …
I have to memorize that expression 😉
