Issue with cut_with_mesh() deleting vertices unexpectedly

[Linus-Foley]

I have a U shaped object, and I wish to cut off a section of one of its ends. I'm trying to do this by placing a rectangle at the place I want to slice at, and then using cut_with_mesh() using the rectangle. As you can see below, the opposite side of the U shape gets some of its vertices deleted.

Is there a way to prevent this, or another way to go about cutting off one end of a U shape?

[marcomusy]

Sorry for the late reply,
When you use cut_with_plane() the Plane is defined in 3d space by its normal so it's an infinite plane.
Consider using cut_with_box() or cut_with_mesh() instead.

[Linus-Foley]

Hi Marco, this bug is occurring with cut_with_mesh(), not cut_with_plane().

If it's useful, here's the shapes to reproduce the problem. I'm just doing half_torus.cut_with_mesh(rectangle, invert=True)

shapes.zip

[marcomusy]

Oh ok, that is because there is no "inside" of a mesh when the mesh is a plane.
Either try with cut_with_box() or e.g.:

from vedo import *

torus = Mesh("half_torus.stl")
m = Mesh("rectangle.stl").c("blue5")
box = m.clone().rotate_x(90).extrude(-0.2).rotate_x(-90)
box.compute_normals()
box.c("green").alpha(0.2).lw(1).wireframe()

torus.cut_with_mesh(box, invert=1)
show(torus, m, box, axes=1)

[Linus-Foley]

Nice, thanks!