Cutting UV Edges

[Anonymous]

Hi Everybody,

I am using Maya LT.

I have a model made of a few subojects.

I am used to unwrap within Roadkill.

Presently I am encountering a few troubles with the unwrapping. So I decided to use Maya instead.

I unwrapped the very first subobjects pretty well.

Now I am unwrapping another subobject but nothing happens anymore: when I cut edges, nothing is displayed, nothing happens.

The seams are displayed for the other subobjects.

Do you have any idea ?

Thanks a lot.

[Anonymous]

There are other subobjects that do not display UV Edges.

There are also subobjects that display the UV Edges.

Weird ...

[mspeer]

Hi!

Please add screenshots and a maya scene-file.

[Anonymous]

Hi,

Thanks for reply.

Sometimes it runs, sometimes it doesn't: I mean when selecting an edge and cutting it, it's possible to see the seam.

I tried to unfold. Nothing happened.

Here is the Maya file.

[Anonymous]

Hi again,

I have a question: to unfold do I need to cut all the edges needed or could it run with partial selection ?

Thks.

[sean.heasley]

Hi @Anonymous

Thank you for attaching the scene file!

It looks like there's some non manifold geometry as well as faces on top of each other that could be causing the issues with your UV mapping.

I'd recommend cleaning the mesh up first and then attempt to UV again!

Here's one example of when I moved a face and found a second one on top of it.

Please let me know if you need any more assistance!

[Anonymous]

Hi,

Thank you very much for reply.

Effectively there were some ngons.

Now the cleanup seems to be OK.

A question please: I have some cut edges that I would like to remove.

I select these edges and then sew UV edges but nothing happens. Is there another way to do it ?

[sean.heasley]

It depends where the edges are on the mesh.

If you don't see 2 edges highlighted when you select one then it isn't going to sew.

I'm currently trying to clean up your model but the model has a lot of errors like vertices not merged and faces on top of each other like in the picture below.

Ultimately the reason you're having these issues with UV mapping is because of the model so you'll really want to go through and make sure theres no duplicated faces, ngons, or non merged vertices like in the picture I shared and then try UV mapping.

It might take me a bit, but I'm gonna try and cleanup your model the best I can and then map it to see if there's any other issues.

[Anonymous]

thank you so much !

[sean.heasley]

Hi @Anonymous

I went ahead and made a quick screencast just highlighting a few of the problems with your model and how to fix them!

This information should help you be able to clean up your model quickly and get back on track to UV mapping 

If one or more of these posts helped answer your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

Kudos are greatly appreciated. Everyone likes a thumbs up!

[Anonymous]

Thank you very much.

I discovered something weird.

The cut edges I wanted to delete in Maya DO NOT SHOW UP in Roadkill.

Please refer to the attached pictures (green rectangle).

[sean.heasley]

Hi @Anonymous

Yeah this is most likely due to the geometry of your model. If there are any issues with the model things like Roadkill will pick up on them by giving results like the one you attached.

Once the model is properly fixed those issues should not appear.

[Anonymous]

Hi Sean,

The workflow is that I made this object from a high poly version that has the same issues you mentioned.

I made it very quick without paying attention ...

Here is the Scene file including HP and LP.

But as you can see, the high poly is UVed.

Thanks again for your help.

[sean.heasley]

Hi @Anonymous

Did you manually create the low poly or did you use a tool like the Reduce tool in Maya?

I'm actually surprised you're making a low poly for a mesh like this, 716 tris isn't that much on your high poly.

[Anonymous]

@sean.heasley

First of all I deleted the tris and then reduced the geometry on the borders.

I didn't use any tool in Maya.

[Anonymous]

@sean.heasley

About the small Piece you mentioned in the Video, I prefered starting from a cube, adding 2 edge Loops and extruding.

[Anonymous]

@sean.heasley

Hi Sean,

I fixed many issues on the mesh.

I tried to unfold in Maya without any success.

So I did it in Roadkill and reimported into Maya.

As you can see the result is very bad due to a lot of stretch.

More than that the seams are not the same in Maya and in Roadkill.

It's really disturbing.

If you have some idea ...

Thanks a lot.

[Anonymous · Accepted solution]

@sean.heasley

I made automatic unwrapping and I've got good result I think.

Please see attached file.

It's a Little bit frustrating not getting the same result manually.

[sean.heasley]

Hi @Anonymous

Automatic unwrap can work but usually you want to use that as a starting point. From there you would want to mark edges and move and sew them together.

Here's some articles on UV mapping that can help!