timfagan Posted December 11, 2015 Share Posted December 11, 2015 (edited) I'm wondering if anyone has figured out how to solve this problem with the extrude sop? I have a trace of the letter C, and I would like to add an inset with the extrusion. However the result has overlapping polygons. Is there a way to correct this? I thought it might be to do with the normals but they're all in the same direction... Edit: What I'm trying to get is the extrusion meeting in the middle of the letter.... Edited December 11, 2015 by kayman Quote Link to comment Share on other sites More sharing options...
timfagan Posted December 11, 2015 Author Share Posted December 11, 2015 ...A resample node before the extrusion cleans it up a bit. I'm still not sure how to clean up the edges. Quote Link to comment Share on other sites More sharing options...
konstantin magnus Posted December 11, 2015 Share Posted December 11, 2015 I dont think there is a problem with the extrude SOP. an extrusion is just moving new points along normals regardless of intersections. what you are probably looking for is a solution for creating "straight skeletons". http://forums.odforce.net/topic/14151-roof-generator/ https://en.wikipedia.org/wiki/Straight_skeleton Quote Link to comment Share on other sites More sharing options...
timfagan Posted December 11, 2015 Author Share Posted December 11, 2015 Yeah looks spot on, thanks for the tip Konstantin. Quote Link to comment Share on other sites More sharing options...
timfagan Posted December 12, 2015 Author Share Posted December 12, 2015 Also with the polyextrude, what you say makes sense, but anytime an inset is applied with a high angle between adjacent edges, it seems there's going to be overlapping polygons, as in the ends of the 'c' above. Is that right? I'm sure there's a way to correct for it, I don't know what it is right now... Quote Link to comment Share on other sites More sharing options...
konstantin magnus Posted December 12, 2015 Share Posted December 12, 2015 (edited) in order to avoid overlappings you should keep the number of edges low (this is especially true for corner regions). a refine SOP can get you there. you can also convert the extruded polygons group to a point group and snap those inner points together. that way you should be able to approximate the requested middle line for the letter C. C.hipnc Edited December 12, 2015 by konstantin magnus Quote Link to comment Share on other sites More sharing options...
timfagan Posted December 12, 2015 Author Share Posted December 12, 2015 Haha that's really cool, I haven't seen those sops used in that way before. thanks again. Quote Link to comment Share on other sites More sharing options...
timfagan Posted December 12, 2015 Author Share Posted December 12, 2015 (edited) If I wanted to smooth that middle line/edge, can I resample just that line somehow? I've managed to isolate the line through either a group SOP, but can't seem to resample it. Or I can delete everything except those middle line points and resample them, but I'm not sure how to reinsert them back to the mesh... (The resample node has that option to treat polygons as Interpolating Curves, which smooths out the line as it inserts points.) I've fiddled around with the connect adjacent pieces and using that to try to form a polygon mesh. I also tried converting them to NURBS curves, and skinning them together, but they don't connect correctly. C_smooth.hipnc Edited December 12, 2015 by kayman Quote Link to comment Share on other sites More sharing options...
konstantin magnus Posted December 12, 2015 Share Posted December 12, 2015 (edited) while i still dont quite get what youre after in a broader sense, i would suggest to start with a clean center line and extrude from that. reducing complexity in a meaningful manner is often times harder than increasing it. C2.hipnc Edited December 12, 2015 by konstantin magnus Quote Link to comment Share on other sites More sharing options...
f1480187 Posted December 17, 2015 Share Posted December 17, 2015 There is rough asset (still at subnet stage, actually) based on the Poly Expand 2D node which is that straight skeleton stuff added in H15. Not very usable currently due to lot of segfaults and infinite cooks on my 15.0.273 build, but the basic setup maybe will work for you. offset_extrude.hipnc 1 Quote Link to comment Share on other sites More sharing options...
timfagan Posted December 28, 2015 Author Share Posted December 28, 2015 Thanks guys, yeah I found the polyexpand2D to be pretty useful as it avoids the overlapping when extruding in a flat plane. Quote Link to comment Share on other sites More sharing options...
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