Contouring

Generate iso-lines or -surfaces for the scalars of a surface or volume.

3D meshes can have 2D iso-surfaces of a scalar field extracted and 2D surface meshes can have 1D iso-lines of a scalar field extracted.

from pyvista import examples
import pyvista as pv
import numpy as np

Iso-Lines

Let’s extract 1D iso-lines of a scalar field from a 2D surface mesh.

mesh = examples.load_random_hills()

contours = mesh.contour()

p = pv.Plotter()
p.add_mesh(mesh, opacity=0.85)
p.add_mesh(contours, color="white", line_width=5)
p.show()

Out:

[(32.59238063266725, 42.5923804083449, 36.404716943411536),
 (0.0, 9.99999977567765, 3.8123363107442856),
 (0.0, 0.0, 1.0)]

Iso-Surfaces

Let’s extract 2D iso-surfaces of a scalar field from a 3D mesh.

mesh = examples.download_embryo()

contours = mesh.contour(np.linspace(50, 200, 5))

p = pv.Plotter()
p.add_mesh(mesh.outline(), color="k")
p.add_mesh(contours, opacity=0.25, clim=[0, 200])
p.camera_position = [(-130.99381142132086, 644.4868354828589, 163.80447435848686),
 (125.21748748157661, 123.94368717158413, 108.83283586619626),
 (0.2780372840777734, 0.03547871361794171, 0.9599148553609699)]
p.show()

Out:

[(-130.99381142132086, 644.4868354828589, 163.80447435848686),
 (125.21748748157661, 123.94368717158413, 108.83283586619626),
 (0.2780372840777734, 0.03547871361794171, 0.9599148553609699)]