Surface split

Hello everyone,
I have a question about surface split in Grasshopper.


I have one surface and two curves. I want to split the surface into three parts with these curves. But I don’t know why in my GH there are always only two parts (0-Trimmed surface and 1-Trimmed surface)?

Thanks a lot for your time and help.
surface partition.3dm (108.8 KB) surface partition.gh (24.8 KB)

Can’t read your R6 .3dm file in R5, can you internalize your geometry into the GH file?

Also, due to the intentional incompatibility of R5 and R6, the Subtract component is missing from your GH file… :frowning:

I tried substituting an arbitrary rectangle for the surface but the code failed at the CCX component. The Python isn’t helpful either, and probably not necessary?

Hey @wangyuanyong14,

The planes are almost tangent (but not quite) to the edge of the hole and this appears to confuse the intersection a little bit.

You already have the tangent vectors at the points you’ve sampled on the oval curve, so why not use those directly?

This should result in the surface being trimmed into four parts.

Split should have worked here. I created a bug RH-53471

Sorry, I have not know what’s your meaning. Could you give me a example in Gh?

Actually I want to split the surface using the planes at the Tangent Points.
But I did’t find the tool in GH.

Thanks a lot.

The two new components you’ll require are Unit Z and Construct Plane. Connect the T (Tangents) output of the Divide Curve component to the upper List Item component to get the curve tangents that correspond to the points that you’ve picked, then use the points, the tangent vectors and the world Z direction to construct the planes.

Hopefully this description, along with the screenshot above, will help you figure this out!

I think so. what’s your bug. I can’t open it on my PC.

Thank you very much!

And I’ve got it.

1 Like

The bug report was opened to the public by Will so you can try that link again.
-wim