Color Cycling

Cycle through colors when sequentially adding meshes to a plotter.

Many plotting libraries like Matplotlib cycle through a predefined list of colors to colorize the data being added to the graphic. PyVista supports this in much the same way as Matplotlib.

from __future__ import annotations

import pyvista as pv

Turn on color cycling in PyVista’s theme and set it to use the default cycler.

pv.global_theme.color_cycler = 'default'

List the available colors in the cycler

pv.global_theme.color_cycler

'color'
'#1f77b4'
'#ff7f0e'
'#2ca02c'
'#d62728'
'#9467bd'
'#8c564b'
'#e377c2'
'#7f7f7f'
'#bcbd22'
'#17becf'

Create a plotter and add data to the scene. You’ll notice that each add_mesh call iterates over the colors in pv.global_theme.color_cycler

pl = pv.Plotter()
pl.add_mesh(pv.Cone(center=(0, 0, 0)))
pl.add_mesh(pv.Cube(center=(1, 0, 0)))
pl.add_mesh(pv.Sphere(center=(1, 1, 0)))
pl.add_mesh(pv.Cylinder(center=(0, 1, 0)))
pl.show()

Static Scene

Interactive Scene

Reset the theme to not use a cycler and instead set on individual plotters.

pv.global_theme.color_cycler = None

If you do not want to set a global color cycler but instead just want to use a cycler for a single plotter, you can set this on with set_color_cycler().

pl = pv.Plotter()

# Set to iterate over Red, Green, and Blue
pl.set_color_cycler(['red', 'green', 'blue'])

pl.add_mesh(pv.Cone(center=(0, 0, 0)))  # red
pl.add_mesh(pv.Cube(center=(1, 0, 0)))  # green
pl.add_mesh(pv.Sphere(center=(1, 1, 0)))  # blue
pl.add_mesh(pv.Cylinder(center=(0, 1, 0)))  # red again
pl.show()

Static Scene

Interactive Scene

Further, you can control this on a per-renderer basis by calling set_color_cycler() on the active renderer.

pl = pv.Plotter(shape=(1, 2))

pl.subplot(0, 0)
pl.renderer.set_color_cycler('default')
pl.add_mesh(pv.Cone(center=(0, 0, 0)))
pl.add_mesh(pv.Cube(center=(1, 0, 0)))
pl.add_mesh(pv.Sphere(center=(1, 1, 0)))
pl.add_mesh(pv.Cylinder(center=(0, 1, 0)))

pl.subplot(0, 1)
pl.renderer.set_color_cycler(['magenta', 'seagreen', 'aqua', 'orange'])
pl.add_mesh(pv.Cone(center=(0, 0, 0)))
pl.add_mesh(pv.Cube(center=(1, 0, 0)))
pl.add_mesh(pv.Sphere(center=(1, 1, 0)))
pl.add_mesh(pv.Cylinder(center=(0, 1, 0)))

pl.link_views()
pl.view_isometric()
pl.show()

Static Scene

Interactive Scene

You can also change the colors of actors after they are added to the scene.

ProTip: you could place the for-loop below in an event callback for a key event to cycle through the colors on-demand. Or better yet, have your cycler randomly select colors.

from cycler import cycler

pl = pv.Plotter()
pl.add_mesh(pv.Cone(center=(0, 0, 0)))
pl.add_mesh(pv.Cube(center=(1, 0, 0)))
pl.add_mesh(pv.Sphere(center=(1, 1, 0)))
pl.add_mesh(pv.Cylinder(center=(0, 1, 0)))

colors = cycler('color', ['lightcoral', 'seagreen', 'aqua', 'firebrick'])()

for actor in pl.renderer.actors.values():
    if isinstance(actor, pv.Actor):
        actor.prop.color = next(colors)['color']

pl.show()

Static Scene

Interactive Scene

Tags: plot