I recently came across a user at Odforce who was having issues with subdivision topology after a poly bridge sop.
http://forums.odforce.net/topic/29042-poly-bridge/ [forums.odforce.net]
I tried my hand at recreating the error, and it does seem there is some bug with the polybridge and Subdivide.
Any idea what could be causing this?
Attaching the file as well as a video.
Poly Bridge bug ?
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- nisachar
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- friedasparagus
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Hi,
The poly bridge is happy enough joining everything together if you toggle on the ‘Attach Geometry to…’ options under the bridge parameter tab.
The freak out seems to be happening with the OpenSudDiv method on the subdivide. The Houdini Catmull-Clark works fine, but the open subdiv throws some errors about flipped faces. Orienting the polygons before the subdivide clears this up…
So there is something funny happening.
Here's the file I had a play with
The poly bridge is happy enough joining everything together if you toggle on the ‘Attach Geometry to…’ options under the bridge parameter tab.
The freak out seems to be happening with the OpenSudDiv method on the subdivide. The Houdini Catmull-Clark works fine, but the open subdiv throws some errors about flipped faces. Orienting the polygons before the subdivide clears this up…
So there is something funny happening.
Here's the file I had a play with
Henry Dean
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- nisachar
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Hello,
Thanks. I should have tried the cleanup node to get around the error. OR maybe add a fuse node after the subdivide ( though this way the sharp angle remains )
Both default Houdini Catmull and open Subdiv seem to be throwing up errors, unlike the latter however, the Houdini Catmul version does evaluate ( instead of just swallowing the mesh ;D ) But it doesn't seem to respect the area where the polybridge joins the polygon ( it seems the error is only in one direction of the bridge, the ‘red’side .
I have shown it in the attached video in the earlier post.
Thanks. I should have tried the cleanup node to get around the error. OR maybe add a fuse node after the subdivide ( though this way the sharp angle remains )
Both default Houdini Catmull and open Subdiv seem to be throwing up errors, unlike the latter however, the Houdini Catmul version does evaluate ( instead of just swallowing the mesh ;D ) But it doesn't seem to respect the area where the polybridge joins the polygon ( it seems the error is only in one direction of the bridge, the ‘red’side .
I have shown it in the attached video in the earlier post.
Edited by nisachar - Feb. 28, 2017 09:46:20
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- friedasparagus
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Oh yes, so it doesn't 
I have to admit, my instinct in always to just stick another node down to get round these things (in this case a fuse SOP after the Houdini Catmull subdivide will sort that, but we don't get the smooth subdivide effect)… but it definitely looks fishy. Seems like the clean followed by the OSDiv gives the best results here
I have to admit, my instinct in always to just stick another node down to get round these things (in this case a fuse SOP after the Houdini Catmull subdivide will sort that, but we don't get the smooth subdivide effect)… but it definitely looks fishy. Seems like the clean followed by the OSDiv gives the best results here
Henry Dean
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- nisachar
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friedasparagus
Oh yes, so it doesn't
I have to admit, my instinct in always to just stick another node down to get round these things (in this case a fuse SOP after the Houdini Catmull subdivide will sort that, but we don't get the smooth subdivide effect)… but it definitely looks fishy. Seems like the clean followed by the OSDiv gives the best results here
Hmm.. yeah.
Unticking the ‘orient polygon’ in the çlean' node suggests the bug might be due to polys facing the wrong way in the bridge sop.
Edit : using reverse node for the copied Primitives solved it.
Edited by nisachar - Feb. 28, 2017 13:14:27
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