Imported UV Map has random connections

[waylonion]

How do I fix my UV map such that non connected pieces don’t have a connection when viewed in 2D via the morph functionality?

I exported my mesh from zbrush as an obj file and imported it into blender.
Inside blender, I created a set of seams and UV unwrapped it and re-exported out a new obj file.

I then imported back the new mesh with the included UV maps. The 3d view looks fine, however when I morph the UV map, I see several weird connections. The connected pieces actually do fit together - for example, the eye socket points to two tiny eye pieces that I cut out.

However, I don’t know why they are connected and am wondering if there’s a fix for this?

The 3D view of the mesh looks fine:

The UV map looks fine in Blender:

[zber2]

Hi @waylonion

ZBrush doesn’t like the UV islands touching the border of the UV space. Scale or move the islands in from the edges a bit.

[waylonion]

Thanks for the suggestion! I tried repacking my UV maps in blender with a larger margin (0.1 as opposed to 0.01 units).

Unfortunately, in ZBrush, it still looks mangled:

I’m not sure if this means anything - but mid-morph, the connections disappear:

One other detail is that the model in zbrush is currently more than 2 units tall (by a little bit). Though I’m not sure if this would matter.

In comparison, the UV map in substance painter looks fine so I’m thinking the problem is still in importing into zbrush?

[zber2]

Another user had a similar problem in this topic and found a solution. I’m not 100% sure what he meant though.

[waylonion]

One other thing that might be important is that my “export level” mesh is sub-division 2 in zbrush.

I have one lower level that I initially imported from the retopology phase. But when I’m now exporting and importing between blender and zbrush for UV mapping, I’m using sub div level 2.

[waylonion]

Oh!! That might be it! Thank you for the pointer!
I suspect then, it might be that I’m importing/exporting at a level higher than the lowest level. I’ll give that a try.

[zber2]

Good! I hope that does the trick for you! Keep in mind though that ZBrush doesn’t like the uv islands touching the uv space border because that will produce similar results. Good luck!

[waylonion]

I created a copy of my tool and deleted the lowest level on the body subtool. Re-importing the UV map worked! Thanks again!