Problem with cut with sphere:

[chuotbach2020]

I used the following code to cut a shape, and the cut surface is clearly visible:

import vedo as vd

disc = vd.Disc(r1=1, r2=1)
# mesh = disc.extrude(3, res=100).linewidth(1)
mesh = disc.extrude(12, res=100)

mesh.cut_with_sphere([1, -0.7, 2], r=1.5, invert=True)
vd.show(mesh, axes=1).close()

But when I switch to using a Cylinder with height=12.0, I don’t see any cut:

import vedo as vd

cyl = vd.Cylinder(
    pos=(0, 0, 4),
    r=1.0,
    height=12.0,
    axis=(0, 0, 1),
    cap=False,
    res=50,
    c='teal3',
    alpha=1.0
).linewidth(1)

cyl.cut_with_sphere([1, -0.7, 2], r=1.5, invert=True)

vd.show(cyl, axes=1).close()

However, if I change height=2.0, then the cut surface becomes visible.

How do I fix this?

[marcomusy]

hi, it is a resolution problem ( a surface cannot be cut if it doesn't contain vertices ( though it may contain faces).
Try

import vedo as vd

cyl = vd.Circle(r=1, res=100).extrude(4, res=100).triangulate()
cyl.cut_with_sphere([1, -0.7, 2], r=1.5, invert=True)
sphere = vd.Sphere(pos=[1, -0.7, 2], r=1.5, c='red', alpha=0.5)

vd.show(cyl, sphere, axes=1).close()