Maya 2017 Serious problem with uvsets which don't use the default "map1" name

[NandoStille]

I will start with a simple hopefully reproducible demo to outline the topic.

Create a primitive cube, rename its uvset to a custom name, duplicate the cube and merge with the first one. The result will have again a default "map1" uvset along the one you renamed. But this one is neither shown in the UVEditor nor in the UV Set Editor. But it's in the list of UVSets in the context submenu and a command query will also reveal, that it is there.

There are quite annoying consequences of this behavior or let's call it Bug now.

For example it also happens with models, like stock models, which were done in another software and now come over to Maya via .fbx and the uvset may be named "UVChannel_1". If you do a Poly Separate on such a model, it will also generate this kind of "hidden" map1 uvset on each separated mesh. And now comes the best: if you export one of those separated meshes in a Maya scene format via "Export Selection" and Import it again the "map1" uvset will be the Current one! And it's empty.

What's going on here?

polyCube -n "testcube1";
polyUVSet -rename -newUVSet "renamedmap1" "testcube1";
duplicate -rr -n "testcube2" "testcube1";
polyUnite -ch 1 -mergeUVSets 1 -name "mergedCubes" "testcube1" "testcube2";
polyUVSet -q -allUVSets "mergedCubes";

// Result: map1 renamedmap1 // 

[NandoStille]

Things are getting worse. The bug also happens with Alembic Export or Import. Not sure at which stage exactly.

Steps to reproduce:

1. create polygon cube

2. rename the default "map1" uvset to something different, like "renamedmap1"

3. Export as .abc. Make sure to enable UV Write.

4. Make a new scene and import the .abc

The cube will now have a "map1" uvset again alongside "renamedmap1" and even worse, "map1" has index 0.

Best for last: It seems the "currrent uvset" feature is also broken.

For the example "polyUVSet -q -cuv" will reveal, that "renamedmap1" is still the current uvset, BUT if you connect a texture, it won't make use of it. It is using "map1" which is empty as we know. The only way to deal with this situation is to copy the uvs over to the so-called default uvset "map1" which came from nowhere.

I am so confused now. Didn't we use this feature in former times to flag a uvset to make it the one which then would be used by the textures? Because it is really doing nothing to what is rendered or shown in the Textured View.

I'd like to add this post. It got me angry. It's about just the same topic and best it's from 2009! Again, 2009! Holy Houdini!

http://forums.autodesk.com/t5/maya-modeling/uv-texture-editor-issues-with-map1/m-p/4080907

[cornelh]

@NandoStille

Thank you for reporting his to us, as you might already know this has been logged as defect ID MAYA-80497, as is currently being dealt with by our Maya QA and Development teams.  Thank you again for bringing this to our attention "again" as it look like this was an issue a while back, hopefully that will add urgency to the fix.  Again thank you for your patience and understanding as we try to iron out all the kinks.  Best of luck on your projects!

[LisandreLF7V9]

@cornelh  i do have the same issue in maya 2022, do you have a solution