Strange poly-smooth\subdiv results.

# 1 03-09-2011 , 04:17 AM

Registered User
Join Date: Jun 2008

Posts: 26

I know it's a bit cliche', but I'm modelling a car. This one is a Nissan Skyline R32 GTR. It's a fairly boxy car, so it should be simple enough to model. It's my first car, so you gotta bare with me a bit.
Anyway, I'm currently working on the door. The unsmoothed mesh looks fine, as pictured here:

user added image

But when I smooth it, the edge of the mesh does something weird and unexpected:

user added image

Here's a closer look at that, it's messy:

user added image

I've checked the normals, and they seem to be.. well... normal, and facing the right way. If any of you Maya modelling gods/goddesses out there can shed any light on this, I will love you with the energy of a thousand suns. I've checked the normals, and they seem to be.. well... normal, and facing the right way. I really wanna see this project through to the end. Thanks in advance guys.

Last edited by s1acker; 03-09-2011 at 05:52 AM.

Quote

# 2 03-09-2011 , 07:18 AM

The thin red line
Join Date: Aug 2009

Location: England

Posts: 4,472

Did you do any belels on the mesh..........dave

Avatar Challenge Winner 2010

Quote

# 3 03-09-2011 , 12:08 PM

Moderator
Join Date: Jan 2004

Location: Michigan, USA

Posts: 2,998

Turn "Keep Border Edges" off

You can also get odd results with "Keep Selection Border" on, So try turning both off ans see if this fixes things.

KBE is trying to literally keep the exact shape of the outer boundary edge and that is the most likely cause of why you are getting oddness around the perimeter of the door.

Here is a test I made and you can see similar results to what you are getting in the first image with KBE=on (default). The second image is more as you would expect and has KBE=off.

Attached Thumbnails

Click image for larger version

Name: KBE_on.png
Views: 347
Size: 79.9 KB
ID: 48455

Click image for larger version

Name: KBE_off.png
Views: 353
Size: 77.5 KB
ID: 48456

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

Last edited by ctbram; 03-09-2011 at 12:34 PM.

Quote

# 4 04-09-2011 , 12:21 AM

Registered User
Join Date: Jun 2008

Posts: 26

Did you do any belels on the mesh..........dave

Originally Posted by daverave

Bevels? If that's what you mean, then I guess I did. The edge would be considered "beveled" because of of the 3 edge loops I made next to the edge of the door to make it so it holds its shape when its smoothed or converted over to subdiv.

Quote

# 5 04-09-2011 , 12:23 AM

Registered User
Join Date: Jun 2008

Posts: 26

Turn "Keep Border Edges" off

You can also get odd results with "Keep Selection Border" on, So try turning both off ans see if this fixes things.

KBE is trying to literally keep the exact shape of the outer boundary edge and that is the most likely cause of why you are getting oddness around the perimeter of the door.

Here is a test I made and you can see similar results to what you are getting in the first image with KBE=on (default). The second image is more as you would expect and has KBE=off.

Originally Posted by ctbram

Thanks so much. Very very helpful. Though I did forget to mention one thing... it does the same thing when you convert it over to subdiv. The poly ---> Subdiv conversion tool doesn't really have much in the way of options. Currently trying to figure this one out at the moment, but I'm sure it's the same deal as the smooth tool. Again, thanks a lot.

Quote

# 6 04-09-2011 , 03:24 PM

Technical Director
Join Date: Feb 2004

Posts: 2,988

You don't need to use Subd's from cars. Just smooth the model. It's better to build the details into your base geometry.

Imagination is more important than knowledge.

Quote

# 7 05-09-2011 , 09:11 PM

Registered User
Join Date: Jun 2008

Posts: 26

You don't need to use Subd's from cars. Just smooth the model. It's better to build the details into your base geometry.

Originally Posted by NextDesign

I guess I just like to know the ins and outs of why things work or don't work. Maya can betray you quickly if you don't know what does what.

Quote

Strange poly-smooth\subdiv results.

Posting Rules Forum Rules

Similar Threads

Topics

Free Courses

Full Courses

VFX News