Get normal vector in the middle point of a trimmed curved surface

Hi all,

I am trying to get the normal vector from the middle point placed in a trimmed surface. I’ve just realized that the Evaluate Surface component only works with untrimmed surfaces. I looked into the forum but I did not find anything useful for this case.

Does anyone know a workaround to get the middle point of a trimmed surface and then the normal vector? Is there any GH component that works as the Evaluate surface but with Trimmed surfaces?

Thanks in advance!

Trimmed Surfaces.gh (33.2 KB)

shrink_trimmed_surface_c.gh (7.6 KB)

Try this…

Sorry @martinsiegrist do you mind copying the code to a native GH python/c# component? I cannot open it, I need an additional plugin.

I’m using Rhino 8

private void RunScript(Brep F, ref object shrinked)
  {
    F.Faces.ShrinkFaces();
    shrinked = F;
  }
1 Like

missing
(too late)

1 Like

You could do it this way:


Trimmed Surfaces_2024Jan2a.gh (33.4 KB)

1 Like

Thank you both for your answers! Different solutions but all equally valid! :slight_smile:

Another way:

Trimmed Surfaces_2024Jan2b
Trimmed Surfaces_2024Jan2b.gh (31.3 KB)

1 Like