PolyData from vertices and faces not working - either crashes or shows nothing about pyvista HOT 3 CLOSED

Figured it out!

When I separated things out and used SetNumpyPoints and SetNumpyFaces, I got a useful error:

Exception: First column should contain the number of points per face

...which I wasn't doing with my faces array. The following now works as expected:

import vtkInterface
import numpy as np
from vtkInterface import PolyData


verts = np.array([[0, 0, 0],
                  [0, 0, 1],
                  [0, 1, 0],
                  [1, 0, 1]], dtype=np.float64)
faces = np.array([[3, 0, 1, 2],
                  [3, 1, 2, 3]], dtype=np.int64)

polydata = PolyData(verts, faces)

polydata.Plot()

As for the example code, which of course does do the faces correctly, the faces refer to a vertex index 4 that doesn't exist... adding that 5th vertex allows the example to not crash:

import numpy as np
import vtkInterface

# mesh points
vertices = np.array([[0, 0, 0],
                     [1, 0, 0],
                     [1, 1, 0],
                     [0, 1, 0],
                     [0.5, 0.5, 1.0]])

# mesh faces
faces = np.hstack([[4, 0, 1, 2, 3],  # square
                   [3, 0, 1, 4],     # triangle
                   [3, 1, 2, 4]])    # triangle

surf = vtkInterface.PolyData(vertices, faces)

# plot each face with a different color
surf.Plot(scalars=np.arange(3))

from pyvista.

Thanks for pointing this out.

I probably should add some error checking code that gives the user a useful error rather than just crashing the interpreter. Doing this check will probably be slow, so I might just implement it in Cython. There's a bunch of other functions that I've been meaning to move over from some of my internal work into vtkInterface, so maybe this is a good chance for me to do it.

Any other recommendations?

from pyvista.

Finally cleaned up the code. Thanks for pointing this out.

from pyvista.