edge indexing does not work properly, or what do I do wrong?
extendsurface edge indexing problem.gh (91.8 KB)
extendsurface edge indexing problem.gh (91.8 KB)
probably that index indicates the direction North, East, South, West, not the edge index
I say so also because if you set the integer 4+ the component crashes
I don’t really understand this North, East, etc… concept. It can have two different solution depending on which side we are looking at. How do we know which is the viewing direction?
X is east, Y is north.
it’s about the UV direction of the surface
North is along increasing V:
East is along increasing U:
South and West are in the opposite directions, you can test it with someling like this (also play with the shift list at the beginning and you’ll see sort of unpredictable stuff on the resulting UVs)
UV_and_cardinals.gh (22.3 KB)
anyway, if you want to extend let’s say just one side of a surface and you don’t really know which North South East West direction to chose, just pull a point on the Surface edge you want to extend, find the (Reparametrized) UV location of that point on the surface, and that will give you the extension direction:
_,1 = North
1,_ = East
_,0 = South
0,_ = West
1 Like
Sounds very inconvenient and confusing indeed!
does not work for me. If 0 = north than it should be a different edge. It is actually East.
north problem.gh (107.9 KB)
in the past I have used it with something like this logic, worked pretty well
usually you can’t just guess the UVs by watching a Surface, because they also depend on how it was created, so using a “helper” like an external point projected on the Surface solved the problem for me
Here is a thing that extends or shrinks a surface in either the U (white) or V (blue) directions.
extend_srf_2024Aug27a.gh (130.6 KB)
No plugins.
Thank you Joseph! It will take same time until I understand this. 
1 Like
Hi Inno,
Thank you very much for your work!
1 Like
also you can use this script @Balazs
or this component in flexibility plugin
Same thing as yesterday but producing a single surface, and clustered.
extend_srf_2024Aug28b.gh (131.1 KB)
No QA testing, might break with some surfaces.
I have tried it with trimmed surface, but it does not work. Is it a problem that it is trimmed? Is there a solution for that?
extend_srf_2024Aug28b TRIMMED.gh (320.2 KB)
Your untrimmed surface is absurd! RIDICULOUS 
Did it take you four days to break it?
You could have spent that time solving it instead. 
extend_srf_2024Sep1a.gh (323.2 KB)
Apparently not. I corrected the previous post.
If you don’t care how it works and are happy with magic black boxes, plugins are for you.
I don’t really understand. For me it does not do what is on your screen.
Too bad, it works for me in R7 and R8. Try nudging the ‘uvDivs’ slider?
I can imagine improvements to handle this absurd untrimmed surface, or you could just avoid the absurd untrimmed surface.
Maybe it is a misunderstanding, I dont need the absurd untrimmed surface. I need to extend only the little portion of it.
I think It is possible to imitate the trimmed surface with FourCurve and use PullCurve to the trimmed surface at least in one direction.