Distance Quantities

Visualize distance-valued data at the elements of a surface mesh.

Distance quantities are basically scalars, but are visualized with alternating stripes to show distance contours.

Example:

import numpy as np
import polyscope as ps
ps.init()

N_vert = 100
N_face = 250
vertices = np.random.rand(N_vert, 3) # (V,3) vertex position array
faces = np.random.randint(0, N_vert, size=(N_face,3)) # (F,3) array of indices 
                                                      # for triangular faces

ps_mesh = ps.register_surface_mesh("my mesh", vertices, faces)

dists = # your distances, a length N_vert array

# visualize the distance
ps_mesh.add_distance_quantity("distances", dists, enabled=True, stripe_size=0.01)

# use defaults for signed distances
ps_mesh.add_distance_quantity("signed distances", dists, signed=True)

# view the mesh with these quantities
ps.show() 

SurfaceMesh.add_distance_quantity(name, values, defined_on='vertices', enabled=None, signed=False, vminmax=None, stripe_size=None, stripe_size_relative=True, cmap=None)

Add a distance quantity to the mesh.

  • name string, a name for the quantity
  • values a length N numpy array, distance scalars
  • defined_on for now, only 'vertices' is supported
  • signed boolean, if true the data is assumed to represent signed distances, and symmetric ranges/colormaps are used by default

Additional optional keyword arguments:

  • enabled boolean, whether the quantity is initially enabled (note that generally only one quantity can be shown at a time; the most recent will be used)
  • vminmax a 2-tuple of floats, specifying the min and max range to colormap in to
  • stripe_size float, the width of stripes in the visualization
  • stripe_size_relative boolean, if true stripe_size is interpreted relative to the scene length scale, otherwise absolute
  • cmap string, which colormap to use

if not specified, these optional parameters will assume a reasonable default value, or a persistent value if previously set.