Integrating 3D models with photography
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# 1 25-10-2007 , 11:16 PM
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Join Date: Mar 2007
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Mesh has an unwanted "second body"

I'm using Maya 8.5
Windows XP Pro on a Dell Precision 690
My pet's name is Billie.

I have a poly mesh I have been building and at some point it took on some strange attribute which i can't fix.

I discovered it when I tried to convert to a subdiv. The script editor told me there was an edge that wasn't right and gave me a command to fix it, which I did. Everything seemed to be running smooth at that point. However, in subdiv I tried to add a big crease and was doing the procedure properly when I noticed that the crease I was creating was only in a second poly that occupied almost the same space as my mesh -- like a second skin, not quite alligned in some places.
If I select two of these overlapping verts, it will tell me I have selected 1 vert and not two, though visibly I see two.

I converted back to a polygon which visibly removed the second skin type issue. However, If i applied a smooth node or went back to sub div, it instantly remanifested. Also, with the smooth node on, if i translate the mesh, the smooth mesh and the original mesh actually separate visually, but can't be separated as meshes. If I select the faces of the smooth mesh and delete them (trying to clean up this strange mess) I get an error message stating: "Warning: Cannot delete non-DAG dependency node 'polyChipOff2' when components are being deleted". However, the faces of the smooth mesh do dissapear, yet my original mesh continues to create (or make visible) this second skin in subdiv or smoothed.

This polyChipOff2 is the only record in the script I can find of what this second skin thing is. Any idea how to fix my mesh so I can get on with business? I hope I've described this well enough for you to understand what is happening.

I've tried Mesh > Clean up. I've checked normals, I've restarted the program. Other poly meshes in the same scene completely normal. I'm not sure when this problem began, only when I first noticed it. I can say at one point before this problem began I extracted part of the mesh (select > faces, Mesh > extract) to better sculpt the area around it (removed an arm from the torso). This may have led to the cause of the problem. I don't know. However, another strange thing is that now when I try to go to Mesh > Separate to create two separate polys of the arm and body that are visibly separated, it tells me I have only selected one mesh and can't separate them. Another problem I think connected to the over all mystery.

To try to fix the issue I went back to an earlier saved version of the mesh. It looked fine. I converted to a subdiv. When I do this the mesh is suddenly broken up in to areas where it's just a wire frame and others where the faces are visible. However, if I tumble the mesh it looks fine and as a subdiv, seemingly works fine.

Then when I converted back to a poly the new poly had the appearance of having had a smooth node applied -- many more polys in the mesh. However, in areas around some border edges there were extra edges (the way a subdiv has) creating many n-sided quads. When I tried to undo back to the point just before I converted to a subdiv the poly gets that second skin like attribute.

I there anyone who can both read through my awkward description of this problem and offer assistance? Any help would be gratefully appreciated.

# 2 26-10-2007 , 12:15 AM
bendingiscool's Avatar
Join Date: Jul 2006
Location: London
Posts: 567
screenshot and shorted description plz lol!!

# 3 26-10-2007 , 06:40 AM
Jay's Avatar
Lead Modeler - Framestore
Join Date: Feb 2003
Location: UK
Posts: 6,287
Typical subd prob by the sound of it so dont worry.

First off Convert it back to a poly then make sure All your verts are merged. And all history is deleted.

Convert to a sub d. Then in the hypergraph check you dont have any subd Blind data nodes. these are the Subd version of History. Simply delete them.

If the extra mesh is still showing you can also pick it out in the hypergraph and delete it.

you should now be able to switch back and forth between Subd and poly without any hassles and also be able to right click on the subd to show a proxy cage.


# 4 26-10-2007 , 08:02 AM
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Join Date: Apr 2005
Location: Wagga Wagga, Australia
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I have that problem every time i try to use Subdivisions. Just do what Jay said and it should fix it.

"If Less is more then think how much more more would be..."

Winner June 2009 Spaceship Challenge
# 5 26-10-2007 , 10:33 AM
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Join Date: Mar 2007
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Jay and "some Guy", thank you so much. I am very grateful.


# 6 26-10-2007 , 10:08 PM
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Hi guys. OK, new wrinkle. I have removed blind nodes.

Now when I convert back to a poly from subdiv there's no second skin however the face count more than doubles as though a smooth node was attached. Any idea what's causing this and how to correct?


# 7 26-10-2007 , 10:22 PM
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check your conversion options and make sure it is set to Vertices, I think the default is Adaptive.

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# 8 26-10-2007 , 10:29 PM
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That was it. Thank you so much.


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