Obtaining the area of a mesh section

[Omar Alvarez]

I am trying to get the area of the intersection of a mesh with a plane. Right now I am using the following code to get the section:

slice = mesh.section(
                plane_normal=n,
                plane_origin=p,
            )

Is it possible to get instead of the outline of the section a filled polygon? Is it possible to get a mesh from a Path3D?

[Michael Dawson-Haggerty]

Hey, I think you want slice.polygons_full[0].area or sum(p.area for p in slice.polygons_full)

[Omar Alvarez]

Amazing, I will test it out and see if it works!! Thanks a lot!

[Omar Alvarez]

I'm getting the following error:

AttributeError: 'Path3D' object has no attribute 'polygons_full'

[Michael Dawson-Haggerty]

Ah you have to move it to a plane from 3D:

In [14]: m = trimesh.creation.box()

In [15]: s = m.section(plane_origin=m.center_mass, plane_normal=[0,0,1])

In [17]: sum(p.area for p in s.to_planar()[0].polygons_full)
Out[17]: 1.0

[Omar Alvarez]

Works like a charm, just for refererence I ended up with:

slice = mesh.section(
    plane_normal=n,
    plane_origin=p,
)
if slice is not None:
    area = sum(p.area for p in slice.to_planar()[0].polygons_full)
else:
    area = 0.0

If plane does not intersect you get None and it errors out.

Thanks a lot for the help!