Converting Poly to Sub-Ds; having some difficulty

# 1 09-04-2009 , 04:28 AM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

Converting Poly to Sub-Ds; having some difficulty

Ok i have another question:

Now I'm having difficulty converting my polygons BACK to sub divisions. My script editor reads:

Error: polyToSubdiv1 (Poly To Subdiv Node): One or more vertices is nonmanifold.
// Nonmanifold geometry cannot be converted to a subdivision surface.
// To clean up nonmanifold vertices, use Mesh->Cleanup with the nonmanifold option. /

So i went to Mesh and hit Cleanup, but im not sure what it accomplished. I tried converting again but it still didnt work. In the tutorial, Kurt says i might have to raise the number of maximum base mesh faces, but after trying severl numbers, i was still unsuccessful.

Any suggestions would be strongly appreciated. I will keep experimenting. Thanks!

Last edited by nick@koeppen.net; 09-04-2009 at 06:16 AM.

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# 2 09-04-2009 , 05:06 AM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

Now the script editor says there are duplicate edges, but i dont know how to find the duplicate edges, i went through my model several times but couldnt find anything.

I tried tweaking the maxpolycount, and have just fixed up any geometry that may be a problem-well at least to a newbie's eyes.

But anyway, still cant seem to convert from polygons BACK to Sub-Divisions, and im really anxious to continue the tutorial.

user added image

Last edited by nick@koeppen.net; 09-04-2009 at 04:37 PM.

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# 3 10-04-2009 , 02:04 AM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

My script editor says:

One or more duplicated edges were present.
// Repair the duplicate edges by selecting the polygon
// and issuing the following command, then try again:
select .e[802] ;string $v[] = `polyListComponentConversion -fe -tv`;select $v;polySplitVertex;polyMergeVertex -d 0.0 -tx 1; //

How do i find my duplicate edges? And how do i issue that command? Someone help? user added image

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# 4 10-04-2009 , 07:25 AM

Registered User
Join Date: Jun 2008

Location: Dhaka, Bangladesh

Posts: 168

about NMG ctbram helped me..though i could not deciphered wht he said..i might help u...let me know if u had figured it out!

ctbram said:
Non-manifold geometry - If cleanup messes up the model. Try using the polygon select tool, checking for NMG. It will highlight the problem and you can try to manually fix it.

In many cases the only real solution is to delete the offending region and simply remodel it.

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# 5 10-04-2009 , 06:24 PM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

Thank you very much for your response- i haven't quite figured it out yet.
There was a very nasty bit on my model that was just completely tangled and confused and i was pretty sure that was the mess. All other geometry seemed to flow quite smoothly. So after seeing if i could salvage the bit by going in there and rearranging, (and failing) i just deleted it and am remodeling it. Im gonna see ifi can upload a picture of what i have now.
However, i tried once more to covert it with the mess simply gone, and nothing. I have looked through my model several times, but i will try what you said. I appreciate it very much.

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# 6 10-04-2009 , 11:31 PM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

Alright lemme know if this works. See if this will open up and-yeah. You'll notice that the tip of the bottom jaw is incomplete, it is a hole basically because that whole area was just a complete mess so after trying to go in there and fix it, i just deleted it.

I've never really remodeled a certain portion like that, so i was just experimenting with all the tools. I just extruded all the faces and was planing on merging the vertices to the centre. But i dont understand how that part of the model COULDNT be the problem.

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# 7 11-04-2009 , 12:09 AM

Moderator
Join Date: Jan 2004

Location: Michigan, USA

Posts: 2,998

I will take a look at it.

There are two tools in maya to help -

1. cleanup geometry - select remove nonmanifold

2. select geometry tool - select by constraint option

What is nonmanifold geometry? I have found two simple explanations that I have found useful -

Description 1
It is geometry that can't be unfolded into a flat piece. Examples are two polygons next to each other, with normals facing in opposite directions, two planes that share a single vertex but no edge, and two polygons, with the edge extruded outward from the edge that both share (basically making a "T" shape out of 3 polygons).

Description 2
Manifold models are models where the volume is well defined.
They have the following properties:

Every edge belongs to two faces.
Every vertex is surrounded by one sequence of edges and faces.
Faces only intersect eachother in common edges en vertexes.
There is a material on only one side of a face

Another way of putting it, a manifold object is a shape that you can create in real life. non-manifold objects have qualities, where you have badly defined volumes in your shape, making it impossible to recreate the model exactly that way in real life.

Try this -------------------------------------------------------

As a good example - create a 1 x 2 polygon plane, then select the middle edge and extrude it. Then try to convert it to a sub-d and see what message you get.

Now select the object and then pick cleanup and check the remove geometry non-manifold check box and apply.

The object will be split into two polygon planes along the shared edge.

I will take a look at your geometry and see what I can find.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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# 8 11-04-2009 , 12:59 AM

Moderator
Join Date: Jan 2004

Location: Michigan, USA

Posts: 2,998

Nick,

I took a look at the geometry and found the main problem to be a duplicate edge (see the image below). To fix it I just deleted the polygon, selected an edge, then picked fill hole to replace the poly.

You also have a pair of unmerged verts (see image)

To see border edges select display>polygon and turn on show border edges.

Minor nits:

The geometry at the tip of the upper and lower jaw is a mess. right now you have a bunch of verts all merged to a single point. I'd consider cleaning those areas up a bit - I think Kurt cleans those up in that tutorial at some point.

Also you have a lot of n-gons (for example coming out of the eye corners). Once again I think Kurt cleans these up later in the tutorial.

So fixing one relatively innocuous laminar edge and the model converts to subd.

Other then that you appear to be progressing nicely with the tutorial. I am sure Kurt would be pleased. Go Go Go!

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"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 11-04-2009 at 01:11 AM.

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# 9 11-04-2009 , 07:42 AM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

DUDE THANK YOU! It worked perfectly! Everything. I learned so much too. You made it very clear. Wow, everyone on this site is so incredibly nice.

Thank you very much. You know i think the file i gave you was actually one save sooner because i had deleted the tip of the lower jaw and had merged those vertices, but either way, i never would have seen that border edge, but now i know how to. Im glad Kurt goes over how to clean up those converging points, i dont even remember how they got that way, no idea, just clumsy modeling.

But i now have that much more experience, thank you ctbram. :attn: :attn: :attn: :attn: :attn:

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# 10 11-04-2009 , 07:44 AM

Ironegg
Join Date: Aug 2007

Location: California, U.S.

Posts: 30

You know what, i need to thank iamcreasy, thank you just as mch because i wouldn't have contacted ctbram without you man, thanks!! Appreciate all the help.

My time on this site is starting to become more than my facebook time heheh.

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