broken unfold (2017 update 3)

[Anonymous]

after installing update 3 unfold just doesn't work for me. test it in previous update and maya 2016. 

here is the mel commands for unfolds

unfold -i 1000 -ss 0 -gb 0.5 -gmb 0.5 -pub 0 -ps 0 -oa 2 -us off pCylinder844.map[20:59] pCylinder844.map[82:83];  \\ couses bad result for update 3
unfold -i 1000 -ss 0 -gb 0.5 -gmb 0.5 -pub 0 -ps 0 -oa 2 -us off;  \\worked unfold in previous versions

after it i tryed execute the mel script in update3 without additional pCylinder strokes, and it works as it should

[brentmc]

Something (Nightshade?) has messed around with your preferences and/or Mel scripts so you should probably reset them before installing update 3.

https://knowledge.autodesk.com/support/maya/troubleshooting/caas/sfdcarticles/sfdcarticles/Reset-May...

I am saying that because in Maya 2017 the unfold command is named "u3dUnfold" not "unfold" and Nightshade (which was using the older unfold command) is now integrated into Maya.

--

Brent

[Anonymous]

thanks for replying, "u3dUnfold" is working for unfold 3d and "unfold" for legacy unfolding, i use legacy all the time because it has a control over horisontal and vertical constraint, unforld3d doesn't have such feature 

[brentmc]

Sorry, you are correct. I still think it is most likely a configuration/preference issue.

[Anonymous]

i deleted folder Documents\maya\2017 , restart maya, create default preferences and still got the same results.

i did the quick test, create a cylinder, planar project it's sides,uv cut one edge and do horisontal unfold, get this result

maybe you can try it on your side, if possible?

[brentmc]

I've passed this thread along to QA for investigation. Thanks.

[trevor.adams · Accepted solution]

Hi @Anonymous,

I'm glad you reported this to us - you've identified a valid and reproducible defect in Maya 2017 Update 3.  And yes, this is a regression that isn't reproducible in Maya 2017 Update 2 or earlier.  Thankfully there's an easy workaround solution for you in the meantime, while we fix this bug on our end.

And so what's the bug?  Put simply, running a "Method: Legacy" Unfold operation after selecting all UVs for a UV shell will produce bad results.  For some reason, Maya isn't recognizing that by selecting all UVs for a UV shell, you're essentially selecting the entire UV shell ... and therefore producing incorrect results while unfolding that selection.  Again, this only happens for the legacy algorithm for Unfold, not the new Unfold3D method.  However, if you select the UV shell in the UV Shell selection mask, you'll get the results you're looking for with the legacy unfold method.  For example:

1. Create a poly cylinder primitive

2. Select the UV shell corresponding to the side of the cylinder

3. Project a planar mapping

4. Select an edge and Cut UVs

5. Now instead of selecting all the UVs while in UV selection mask, switch to the UV Shell selection mask (in the UV Toolkit or RMB marking menu) and select the UV shell

6. Unfold using Legacy method and all the settings you described in your screenshot above

RESULT: You get a proper horizontally-constrained unfold.

Again, this is a defect and not an intentional change in behavior.  I've logged it on our end and we'll try and get a fix out in an upcoming release.

So yeah ... good catch!  Thanks again and if you have any further questions or any other problems to report, let me know.  And if the workaround works for you in the meantime, feel free to click "Accept as solution".

[Anonymous]

I'm afraid I'm trying your suggested method and it still produces bent and skewed UV's, If I duplicate the object sometime it'll fix it for one operation and then reverts to giving me skewed UV's again.

Can we please get a fix for this as the legacy unfold is so important for a lot of UV mapping.

Cheers

Chris

[trevor.adams]

Hi @Anonymous,

When I test the steps I described above (default cylinder), I get skewed results in the latest-publicly-available Maya build, Maya 2017 Update 3.  And to work around the issue, I select the UV Shell in UV Shell selection mode - that results in the result you'd want/expect - no skewing.  Are you saying that on your end, in Maya 2017 Update 3, if you follow my above steps & workaround, you're still getting skewing?  Or are you referring exclusively to trying out those steps on your own scene file?  I used your settings from this image:

With those exact settings, I can get this result:

Whereas, I used to get this one (when running Unfold on selected UVs instead of a UV shell, using Legacy method):

Can you share your results?

The workaround is no longer required in our next proposed releases (the in-development builds we're working on for the next couple of versions/updates) - I tested it in both branches on our end and everything works well, so yes this should be fixed in your next update.  That said, I still want to make sure we're talking about the same problem here.  If the workaround still isn't working on your end (both when using a primitive cylinder and when using your own scene files), let me know - feel free to share your scene file so I can better follow along with you.

[Anonymous]

@Anonymous -  The problem noted above regarding Unfold3d (now u3dUnfold in 2017) does not have a workaround if the user is accessing that plugin through the BonusTools: bt_autoUnwrapUVTool.mel script.  That interface starts with object level selection, and as you know converts down through faces and UVs in the script itself, thereby not allowing the user to circumvent the issue via selection of all shell UVs.  On a simple cylinder, all faces aligned along the Up axis are compacted to the origin as seen in the screenshot below. Switching between Y up and Z up appears to switch which faces are compacted down to infinity. 

[Anonymous]

Hello, I am experiencing this exact same issue in Maya 2020 update 1. Is there any solution to this.