3

In this answer you can use two or more curves to generate a loft mesh with geometry nodes, but answers in this thread work for an open surface.

What could be a good approach to close the loop?

enter image description here

vklidu
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    Dang! I knew I should have finished this one up. Until I get to it, you could perhaps trim all curves 0-1 to split them, work with the split curves, weld back at the end? Haven't fully checked it out for reliability. – Robin Betts Sep 15 '23 at 08:40
  • what about simply putting the first and last "column" on same position and then merge by distance? – Chris Sep 15 '23 at 10:24
  • If you want to just close it, can't you spawn a cylinder with matching vertices/edge loops numbers and sample positions by index? – Markus von Broady Sep 15 '23 at 10:42
  • Hi @vklidu This is the quick-fix.. but not chuffed to bits with it: On mixed cyclic and acyclic profiles, UV's can mismatch on cyclic sections, because of length difference at the seam. It relies purely on proximity for re-welding cyclic profiles.. can fail, rarely. However, if you think, too, it is an improvement on previous, so may edit into the other answer. – Robin Betts Sep 15 '23 at 17:16
  • @RobinBetts Thanks ... I tried to split curves, but it messed up ... I checked your file, but my Mac at home is too old, 3.4 crashes with your file and last official 3.31LTS (where I had to replace two nodes to Transfer Attribute node) didn't work either, so there is probably something more missing, but I'm not in a hurry. ... Sure, improve your original answer as you like :) I dont think it is a Q to me :) I just created this thread since I guess it can be achieved in several ways and could be used in other scenarios, so I wanted to keep this topic separate. – vklidu Sep 16 '23 at 08:45
  • @Chris ... isn't it that in this case it destroys the rectangle corner? My GN knowledge is too low, answer with example is appreciated :) – vklidu Sep 16 '23 at 08:47
  • Hi, @vklidu Hmmmm.. shame. Maybe that's because I generated that file with 3.61. Will make another with 3.4. Maybe the whole thing could do with a tidy-up. I, too, look forward to clean, reliable ideas from GN specialists ;) .. if there are better ways out there. – Robin Betts Sep 16 '23 at 08:51
  • @MarkusvonBroady ... yes sounds like the way ... I'm not sure if will be able to match indexes ... so an Answer will be appreciated :) – vklidu Sep 16 '23 at 08:52
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    @RobinBetts ... yes I think it is version reason ... but like I wrote it is not a necessary to make it for old version (even 3.6 becomes old early :) ) for me is this more a study case that I would like to know how to handle it in a future (it is not a project that has to be done yesterday :) but thank you for a quick response :) what a Saturday morning :) – vklidu Sep 16 '23 at 08:56
  • @vklidu: i would try it with an answer if you provide the GN node tree, how you created that geometry ;) or maybe a blend file? ;) – Chris Sep 16 '23 at 11:07
  • @Chris ... Sure Edit ... it's the RobinBett's blend in the mentioned thread. – vklidu Sep 16 '23 at 15:23
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    @RobinBetts ... I got to v3.6 ... works great :) ... just a Trim Curve node ... hm ... – vklidu Sep 16 '23 at 17:09

1 Answers1

3
  1. Duplicate the first spline as the last:

  1. Increase the $x$ resolution of the Grid, to add this one missing column (could be done without step 1, but then you would need index remapping, and this way indices match again):

  1. Change the UV domain to Face Corner, since now you have a column of vertices that are supposed to be both the beginning and the end:

  1. Merge by Distance (if you don't want to, you also don't need p. 3.):

Result:

Markus von Broady
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  • Thanks ... it works great ... just curriouse the Cylinder way didnt work for you? BTW Face Corner want set before already? If Robin is going to post answer here it would be a dilema :) – vklidu Sep 16 '23 at 17:43
  • Thanks, Markus.. I've got a stinking cold / man-flu at the moment, so haven't been able to put the time in. Much appreciated. @vklidu, only difference between this and the trim method is that supposedly the trim will handle mixed cyclic and acyclic? But that has other UV problems of its own. – Robin Betts Sep 16 '23 at 17:47
  • OK will test it ... if it will be reasonable to create answer later for others ... mainly get well soon :) ... man-flu is serious thing, I know that ... – vklidu Sep 16 '23 at 17:57
  • @vklidu I didn't use the cylinder option, because in 3.3 it doesn't generate UV Map. It would look this way: https://i.imgur.com/XGQJm1Y.png unfortunately you can't increase top/bottom fill segments. – Markus von Broady Sep 16 '23 at 18:15
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    @RobinBetts my terrible man-flus ended when I started supplementing iron, apparently most of the population have a deficiency (I've seen a research on magnesium, a carrot today has 10-20% of a carrot a century ago, I imagine it's very similar for many other elements), but obviously one needs to avoid overdosing iron. – Markus von Broady Sep 16 '23 at 18:24