Grasshopper contoured surface region difference


(airoaya) #1

hi i’d like to make surfaces created by crevices that are moved downward by the contour interval

Is region difference not working because the domain value per height is not the same?
0522 (13.3 KB)


Region difference would work if your curves were in the same plane. In this definition, the Z coordinate is different for each curve send to the component.
Maybe offset component would be a better choice than the Move component.

Moreover, your should send curves to the “RDiff” Component and then apply the “Boundary Surfaces” component on the resulting contour.


(airoaya) #3

thanks baptisteC

It works well on a typical homogeneous surface

However, on curved surfaces where the gradient changes, it is necessary to move the curves vertically to make faces
This is because the spacing between the curves is different.

This is the contour surfaces i want to make…
Do you have an idea for this to work?
0523 (34.3 KB)


Sorry, but I don’t understand what you want to do.
Could you draw manually the result that you’re lookin for ?
And add comments to your GH workflow ?

(airoaya) #5

sorry for insufficient information.

I think it’s a good idea to talk in stages.
First, after contouring the surface, the lines are moved vertically by the contoured height
Then I want to make the gap between the contour lines and the vertically moving lines to the surface

0524 (35.1 KB)
0524 contour.3dm (234.1 KB)

(airoaya) #6

I want a surface with a flat surface created by applying these flip matrix

flip matrix swap rows and colums and i dont know why it doesnt work when i use it for swap these surfaces.


Did you find a way to draw it in Rhino first ?
If you find a satisfying solution in Rhino, then you can try to build it in GH and have few parameters to adjust your model.
I did the modeling in Rhino :

The red parts will be easy because curves are closed, (nevertheless, you’ll have to deal with different curves on the same plane). But the blue ones are to be made from open curves, you’ll have to find a way to close the curves before anything else.

In your case, if you want to fill the gaps between your contour curves, you have to find the main logic of your workflow.

  1. You can choose to fill the space between your curves. How will you deal with open curves ?
  2. You can also choose to cut planar rectangles with your contour curves and keep only surfaces that you want. How will you make the difference between a surface to keep and a surface to delete ?

Grasshopper surface split
(airoaya) #8

thanks a lot BaptisteC

I think I need to work on grasshopper for my project
so I will find a way to solve it.
your work helps me a lot