Nurbs curve to surface

Thank both of you guys for your help. I’m training and I now would like to extend the attractor effect from points as you can see on this picture. In fact I want it to be streched following the circular way. Is there a solution ? Maybe with attractors ?

Have a look at this thread:

I made a definition for a smooth attractor

Thanks Tim,

I tried to adapt your file to my radial grid but the pinching result is not concluding :persevere:
It is much more like volcanoes while I want to make a kind of a half biceps shape (15.5 KB)

use curves rather than points for attractors.

You can Play with with graph to get a smoother result. But with a Point attractor, it will always be a circle and not streched in one direction. Try a curves @Michael_Pryor mentioned. You can also try his “Pufferfish” plugin. There’s a Pinch’n’Spread component for attractors. Works better and faster than the “nudibranch attractor”

Changed it a bit, so you get a smoother grid, don’t know if this helps. (15.5 KB)

Hi Tim, thank you for these advices and for your precious help !
The fact is that with curves I can’t get a result as drawn on this picture. It is strait while I want it flared at the center level of the curve. Well now my drawing is obscene :joy:

LOL :smiley:, I don’t believe myself that it’s me who’s gonna suggest that, but…

Try Kangaroo (by @DanielPiker). This looks like a classic case of form-finding.

Thank you Ivelin, I appreciate your help. I can’t find the result I want with kangaroo…
Maybe I can reach my goal by lofting the shape from the other curves.

Like this.

Is it possible to loft from these curves:

From these Nurbs:

Instead of these curves:

Thanks for yout help

can you try placing a point in the center, then use Patch surface command and select all curves plus the point in the center.

Well it works but it’s not making the streched effect… It’s driving me crazy

What is the stiffness you used? Try 0.1

try making more isocurves in one direction. V should be radial


that not how you model with Nurbs. You have no control on curvature, when modelling like this. Curves looking good, but that doesn’t mean that your surface(s) will do. Usually you create an complex shape with more than one surface. Usually you model less curved parts first and blend in between. A good surface layout yields a good curvature flow. I don’t believe you will ever produce something useful using grasshopper here.

:slight_smile: Tom, don’t discourage him.

Perhaps if I had the curves I could try to do it, This is not so complex form to use multiple surfaces.

I’m not discouraging him, at least I hope so :worried:. Its going into the wrong direction, and that is what I’m saying. It might be a better idea, to model a sketch in Rhino, and see if you can do it parametrically in GH.

No one is discouraging me. I just see advices and thank you all for that ! I think grasshopper can make the impossible. Is it possible to make a point a double attractor ? The second attractor could maybe stretch the shape or make it thiner

Ok that really got messy, but I hope you can do something with it. Pls dont look into the file :smiley: The tree Management ****** me up. There is a much simpler way, but at the moment and the 5x5 min, I had time between my work, didn’t let me find a more elegant solution.

If this is still not what you’re after, I can’t help you further. (33.7 KB)

here is a principal sketch how I would do this:

in GH its very difficult, you can however make use of the new fillet functionality or the blend surface command in Rhinocommon (useable by script in GH 1.0+) , its quite challenging though.

Please be Aware, the script is not bulletproof. as soon the regions overlap far each other, you don’t get nice results. I want to replace the “Point in curves” component with something like pull Point, but I don’t know yet, how to seperate the branches for each area.

Tim you are a hero ! Thank you very much this is pretty much the result I expected ! I can’t make your file functional as i’m a newbie with grasshopper but i’m looking into it

out of curiosity, what will that result be?