Visualization (VisMPL) is showing an empty figure

[curiouscivilengineer]

Describe the bug I want to create NURBS/Bezier Surfaces with geomdl. I installed the package via conda and started by trying to run the example given here : https://nurbs-python.readthedocs.io/en/5.x/visualization.html

This is the given code: `from geomdl import BSpline from geomdl.visualization import VisMPL

ctrlpts = [ [[-25.0, -25.0, -10.0], [-25.0, -15.0, -5.0], [-25.0, -5.0, 0.0], [-25.0, 5.0, 0.0], [-25.0, 15.0, -5.0], [-25.0, 25.0, -10.0]], [[-15.0, -25.0, -8.0], [-15.0, -15.0, -4.0], [-15.0, -5.0, -4.0], [-15.0, 5.0, -4.0], [-15.0, 15.0, -4.0], [-15.0, 25.0, -8.0]], [[-5.0, -25.0, -5.0], [-5.0, -15.0, -3.0], [-5.0, -5.0, -8.0], [-5.0, 5.0, -8.0], [-5.0, 15.0, -3.0], [-5.0, 25.0, -5.0]], [[5.0, -25.0, -3.0], [5.0, -15.0, -2.0], [5.0, -5.0, -8.0], [5.0, 5.0, -8.0], [5.0, 15.0, -2.0], [5.0, 25.0, -3.0]], [[15.0, -25.0, -8.0], [15.0, -15.0, -4.0], [15.0, -5.0, -4.0], [15.0, 5.0, -4.0], [15.0, 15.0, -4.0], [15.0, 25.0, -8.0]], [[25.0, -25.0, -10.0], [25.0, -15.0, -5.0], [25.0, -5.0, 2.0], [25.0, 5.0, 2.0], [25.0, 15.0, -5.0], [25.0, 25.0, -10.0]] ] surf = BSpline.Surface()

surf.degree_u = 3 surf.degree_v = 3

surf.ctrlpts2d = ctrlpts

surf.knotvector_u = [0.0, 0.0, 0.0, 0.0, 1.0, 2.0, 3.0, 3.0, 3.0, 3.0] surf.knotvector_v = [0.0, 0.0, 0.0, 0.0, 1.0, 2.0, 3.0, 3.0, 3.0, 3.0]

surf.delta = 0.025

surf.evaluate()

from matplotlib import cm

surf.vis = VisMPL.VisSurface() surf.render(colormap=cm.cool)`

The code runs with without an error.

Expected Behavior It should look like this: But it just looks like this:

The example in 2D work without a problem but as soon as i try to plot a Curve or Surface in 3D it shows an empty figure.

Configuration:

• OS: [Windows 11]
• Python distribution: [Anaconda]
• Python version: 3.10.10
• geomdl install source: Anaconda
• geomdl version/branch: 5.3.1
• I also tried deleting and reinstalling both anaconda and geomdl, without succes

It would be really appreciate your help.