Split operation on Brep does not update domain

Is it possible there is a bug in the Split command for Breps in python?

I am splitting a Brep (Rhino.Geometry.Brep object) using the brepName.Split(surfaceName) command.

When I ask either of the resulting breps for their domain, I end up with the u,v, domain of the original Brep. This should not be, right? T
he same goes for the BrepFace.Split command.
The resulting BrepFaces have the original breps domain.

I only need the domain of the resulting splitted breps.


PS: My breps are planar 2D surfaces.

Hi Lukas- splitting a surface into pieces does not alter the underlying surface size - each resulting face will still have the original underlying surface unless it is shrunk (Rhino command: ShrinkTrimmedSrf).


For future readers:

If you split a brep using python use ShrinkFace on each resulting brep


breps = Brep1.Split(Curve, tolerance)
for brep in breps:
#Its a command available in Rhino.Geometry.Collections.BrepFaceList

Now calling the Domain() command on the face will return the correct domain of the face.

I am confused. Why do you think the domain is incorrect? What problem are you trying to solve?

Hi Dale,

I wasn’t aware that I have to shrink the face before the domain would update.
I am not sure if this is intended.
Anyways when I split the brep, and access its face, it will still have the domain of the unsplit brep.

Why do you need the domain modified? What does this get you?

Ok here’s what I do.

I start with a surface.
I then randomly generate a point on this surface (using the domain and u,v coordinates)
Then I put a line through this point and split the surface.

I do the same for each of the two newly generated surfaces. But to find a point inside the new surfaces I need to have the correct domain.