New problem with subdivision

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Here is a bug or new feature? I made simple polygonal object with polyextrude, added Crease attribute to selected edges. Then I subdivided object. I made many times similar things in previous versions, but now (H15.0.224.16) everything begins unusually. With Flat View in viewport it's OK, but Smooth and Render views makes strange result. But not all so sad. If I remove Subdivide node and turn on Render polygons as subdivision object parameter it seems OK in Render view. What is it? New feature or new bug? If I don't use Polyextrude node, the problem does not occurs. Or if I open old version project (with old Polyextrude) - no problem. What is the reason: new Polyextrude, Subdivide node or my curve hands?

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:shock:
Ummm…..whatchya makin'?
Chris McSpurren
Senior Quality Assurance Specialist
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Same question asked my wife. :wink: Nothing special. Just random sequence of polyextrudes to demonstrate a problem. But after subdivision… Now you see. But in fact I was making a spoon when faced with this problem.
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It looks like you might have hard edges (unshared) along the… uh, extruded thingy. That would explain the non-smooth shading along it.

Turn on “3D Boundaries” (Display options, Markers, under “Draw”) to see if those edges are not shared between adjacent polygons.
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It's a sausage!


I know (because I was told so) displaying boundary edges is computationally expensive for dense meshes, but I think having them enabled for the selection only by default is an artist friendly default.
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On the PolyExtrude nodes, turn off Add Vertex Normals, (or whatever the parameter is called; I don't have it in front of me). That, or, at the end of the chain, delete the vertex N.

Yeah, it's not such a great default for subd modelling; it was requested for modelling objects with hard edges with PolyExtrude. The more permanent solution for this type of work would be to have the viewport and Mantra support computing vertex normals based on object parameters and options. At the moment, Mantra always throws away normals when doing subdivision and recomputes point normals, (which has its own issues, as some have discovered), and the viewport always uses provided normals.
Writing code for fun and profit since... 2005? Wow, I'm getting old.
https://www.youtube.com/channel/UC_HFmdvpe9U2G3OMNViKMEQ [www.youtube.com]
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McNistor, now I understand: it's a sausage monument!
twod, It is not in the hard edges. ndickson is right. Clearing checkbox “Add vertex normal” in Extrude node helps. Also helps Vertex node with “No Normal” before subdivision. Not very logical, it may be worth left unchecked “Add Vertex Normal” checkbox by default in Polyextrude node because people that studying modelling can fall into a stupor. But right now I do not care about it. I studying new Polyextrude. It's revolution in modelling, really!
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