# 5- Parametric Curve Attractor

In this video tutorial, I will explain how you can use u,v coordinate system to produce a parametric curve on a surface and use it as an attractor to affect the frames of triangular panels.

20 Minutes

60 MB

### Free Weekly Scripts

Join our exclusive email newsletter and be the first to receive our free, useful Grasshopper scripts every week!

• ##### Felsager

More tutorials like this should happen more often. The possibilities for further developing this one are almost endless. This generalizes a lot of topics in a single lesson.

Outstanding tutorial.

• ##### rezae

Thank you!
I am grateful for your support.

• ##### Cfeldman

What if you have a “”Polysurface””,and not a ‘Surface’ to apply the LunchBox-plugin and…
finally go to Panelling-Attractor exercise.
How to resolve that ?

• ##### rezae

Hi Claudio
Surfaces are singular and continues which means you can do everything that you could done on 2d space inside rhino you’ll be to do on the surface (instead of x and y , you have U and V) but Polysurface are made from surfaces so you cannot define a point on a Polysurface with just 2 value (like x and y), even though you can have access to each individual surface on a polysurface but aligning pattern on edges would be very difficult .
So I think easiest solution is that you can work on unfolded (expanded) version of your polysurface and then rebuild the generated pattern on the polysurface

• ##### rw3iss

Hi, it is a great tutorial, thank you!
I am wondering if you could advise on how to remove this connecting line attached here…
I changed the arc to an ellipse, to make a complete form, and this line appears during the Loft stage.
I can’t find a setting in the Loft or Weaverbird PanelFrame to have it not show.
If it is a little complicated, can you just briefly explain it? Should I think to remove such a thing earlier on at the loft/curve stage, or later in the Weaverbird construction, or after?
Here is my modified grasshopper definition if it helps: https://drive.google.com/file/d/1bFa92gkGJHSRb9YFzB7LHUQABVkwFxjs/view?usp=sharing

• ##### rezae

Hi, we can not apply this solution on any periodic surface since the pattern is symmetrical on Z axis so the pattern couldn’t wrap around periodic surfaces
thanks

• ##### Bernard

Hi, is there any technique to limit the number of panel dimension, lets say to 10 different panel to build the entire surface?
Thank you

• ##### rezae

Hi Bernard,
I think using “Rectangular Grid” from Lunchbox plugin can be the easiest solution.
Best,