Forums Houdini Indie and Apprentice How to skin 2 surface with different no of pts?

How to skin 2 surface with different no of pts?

   7623   7   1
User Avatar
yul000
Member
9 posts
Joined: 3月 2010
Offline
 
Hi,
I have 2 primitives that are angled and have different number of points. Ive tried to skin, polyloft, polystitch and bridge. All the lofts are intersecting. Can anyone tell me what settings I need to change?

Polypatch works but all e sides are rounded.(I need e original 2 primitives to retain its form)

Attachments:
skincombined.jpg (22.5 KB)

 Report
User Avatar
Soothsayer
Member
874 posts
Joined: 10月 2008
Offline
 
Have you tried the sort SOP?

I can't actually replicate your problem very easily. For me, skinning seems to work with any shape, any point numbering.
--
Jobless
 Report
User Avatar
yul000
Member
9 posts
Joined: 3月 2010
Offline
 
Here im tring to bridge the buildings from the nearest cell to another. But the skinning encounter some problems.

Attachments:
QUESTION.hipnc (188.4 KB)

 Report
User Avatar
Anonymous
Member
678 posts
Joined: 7月 2005
Offline
 
You have to lock file node. Without it, when we open your file, we miss geometry you are working at so we can't help.
 Report
User Avatar
old_school
スタッフ
2540 posts
Joined: 7月 2005
Offline
 
Either Sort or better a Reverse SOP. Just select one profile, tab-Reverse, done.

Dead give-away is in the viewport snapshot. Both primitive normals are facing each other when they should be facing in the same direction.

This is a common problem. You extract two faces from two objects facing each other to bridge. If the two objects are built properly, then the primitive normals will also be facing each other. Skinning primitives with normals that face each other cause that classic bowtie result. Just reverse one of the primitives. That is why the Reverse SOP exists. Just for that purpose.
There's at least one school like the old school!
 Report
User Avatar
yul000
Member
9 posts
Joined: 3月 2010
Offline
 
Thanks swan. Ive locked the geo file. Its attached below.

Jeff. Ive tried reversing the normals in either way. Yet the “bridge” become a bowtie.

So, Ive decided to delete the primitive and resampled it back into a polygon using add. Now i can manage the twist. but the "bridge is in a foreach node. So, some bridges looks fine but some are still twisted. Anyway to set a rule where no twist occur?

Attachments:
question_388[1].hipnc (237.1 KB)

 Report
User Avatar
rmagee
スタッフ
1185 posts
Joined: 7月 2005
Offline
 
The two polygons that you are trying to connect have points that are out of order - the first one goes 0, 3 1, 5, 2, 4 and the other one is 6, 9, 7, 10, 8. This is because these polygons have been extracted from a more complex piece of geometry. So I added a sort node which resorts them by vertex order so the numbers are at least sequential. After testing a skin there is still flipping so I selected only the first six points and reversed them. The resulting surface seems to be what you are looking for.

Robert

Attachments:
question_388_1__111x.hipnc (227.3 KB)

Robert Magee
Senior Product Marketing Manager
SideFX
 Report
User Avatar
yul000
Member
9 posts
Joined: 3月 2010
Offline
 
Thanks u simplify it. Yes this is what i wanted.

In this particular foreach that u did, it works perfectly. However some other “bridges” is slightly twisted(circle in red). Nontheless, its ok for me. thanks

Attachments:
1twist.jpg (37.2 KB)

 Report
  • Quick Links