UV Shells Not Merging When Two Meshes are Combined

[Anonymous]

I have an object, O1, with uv shells in UDIMs 1001-1005. I import an fbx file of another object, O2, with uv shells all in 1001. I move the shells of O2 to UDIMs 1006 and 1007, name all the texture files appropriately, and generate previews. All is perfect. When I try to Mesh->Combine O1 and O2 the shells of O2 disappear and texture 1007 appears in 1001. I have tried all various options in Mesh-Combine. None change this behavior in any significant way. I need O1 and O2 to be the same object because the next step is copying skin weights from a rigged version of O1.

Any ideas or pointers or suggestions welcome!

Thanks,

Greg

[hamsterHamster]

To merge UV shells you also need to merge the geometry, edges/vertices of those seams. Just you did not mention doing it, and Combining alone is not enough.

[Anonymous]

I think I wasn't clear enough. I don't want the uvs of O2 to become part of the uvs of O1 but just to have them appear in the UV Editor in tiles 1006 and 1007 when I select the single new object, say O3, which is the combination of O1 and O2. Right now the uvs of O2 disappear and I do not see them anywhere when I select O3.

I have done this before with multiple objects, separating and combining as necessary and I have never lost any uvs. The difference here is that I imported O2 into a scene with O1 in it.

(also, the construction of O2, not by me, is poor in that each face is it's own uv shell. Have not seen this before.. maybe it's part of the problem?

Thanks,

Greg

[hamsterHamster]

Missing uvs can because they are in a separate uvSets. Have you checked if you have just one?

[Anonymous]

Yes. I have messed around with UVSets and I cannot seem to get the uvs of O1 into the same set as O2. When I do a copy from one set to another the target set only contains the source set *not* both sets. It seems copy is more like replace than merge. Is there a way to merge two UVSets?

Greg

[hamsterHamster · Accepted solution]

I guess you should try again.

First of all, make sure there are just ONE uvSet in each of source objects - O1 & O2. Rename them identically, like 'map1'.

Combine O1 and O2 with Merge By Name option on (default). If you try to merge two uv sets that contain same uv id's, then matching source uvs replace the target uvs.

If still having disappearence, then at the bottom of uvToolkit (in uvEditor) there is an uvSets section. Or, you can use uvEditor's UV Sets menu.

[Anonymous]

Thanks! That worked. I marked your answer as a solution.

Cheers,

Greg