Note
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Moving Isovalue¶
Make an animation of an isovalue through a volumetric dataset
import pyvista as pv
from pyvista import examples
import numpy as np
vol = examples.download_brain()
vol
Now lets make an array of all of the isovalues for which we want to show.
values = np.linspace(5, 150, num=25)
Now let’s create an initial isosurface that we can plot and move
surface = vol.contour([values[0]],)
Precompute the surfaces
surfaces = [vol.contour([v]) for v in values]
Set a single surface as the one being plotted that can be overwritten
surface = surfaces[0].copy()
filename = "isovalue.gif"
plotter = pv.Plotter()
# Open a movie file
plotter.open_gif(filename)
plotter.enable_depth_peeling()
# Add initial mesh
plotter.add_mesh(surface, opacity=0.5, clim=vol.get_data_range())
# Add outline for reference
plotter.add_mesh(vol.outline_corners(), color='k')
print('Orient the view, then press "q" to close window and produce movie')
plotter.camera_position = [
(392.9783280407326, 556.4341372317185, 235.51220650196404),
(88.69563012828344, 119.06774369173661, 72.61750326143748),
(-0.19275936948097383, -0.2218876327549124, 0.9558293278131397)]
# initial render and do NOT close
plotter.show(auto_close=False)
# Run through each frame
for surf in surfaces:
surface.overwrite(surf)
plotter.write_frame() # Write this frame
# Run through backwards
for surf in surfaces[::-1]:
surface.overwrite(surf)
plotter.write_frame() # Write this frame
# Be sure to close the plotter when finished
plotter.close()

Out:
Orient the view, then press "q" to close window and produce movie
Total running time of the script: ( 0 minutes 34.897 seconds)