Select surfaces of a plane

Grasshopper Developer
1

Hello there,
I’m trying to explode a brep in grasshopper and then select the surfaces oriented on the XY plane, and get rid of the other ones… Can somebody help me?

image
image.png1535×812 6.14 KB

as an example. from this

image
image.png1535×812 5.81 KB

to this

2

Hint: Faces with their Normal being parallel or anti-parallel to the Z-unit vector are the ones you want to keep. There are components for all of that.

I don’t have Rhino installed right now (just restored Windows after a total crash, thanks Acronis “Try & Decide” for killing my machine) so I can’t give an example, but that’s one possible strategy.

// Rolf

1 Like
3

Good idea Rolf! thank you
But I still couldn’t figure out how to make it work

image
image1407×710 73.8 KB

4

following with Rolf’s idea I gave a try and got to an answer. :wink:isPlanarToVector.gh (10.4 KB)

5

Doesn’t work very well. A lot of times this method fails.

I do found a solution that works much better:

Sort_Surfaces
Sort_Surfaces1116×295 48.9 KB

Sort_Surfaces.gh (9.6 KB)