Multiscaling (triangle mesh)

The Multiscale class is used to create a multiscale representation of a triangle mesh using quadric decimation. Quadric decimation reduces the number of points of a mesh by iteratively collapsing the edge with the smallest quadric error.

For reference on quadric decimation, see: Garland and Heckbert 1997.

We use the implementation proposed by fast-simplification.

Load a mesh

import pyvista as pv
import pyvista.examples

import skshapes as sks

bunny = sks.PolyData(pyvista.examples.download_bunny())

Create the multiscale representation with different ratios of the original  number of points

multiscale_bunny = sks.Multiscale(shape=bunny, ratios=[0.1, 0.01, 0.005])

Visualize the multiscale representation

plotter = pv.Plotter(shape=(1, 4))
plotter.subplot(0, 0)
plotter.add_mesh(multiscale_bunny.at(ratio=1).to_pyvista())
plotter.add_text(f"N_points={multiscale_bunny.at(ratio=1).n_points}")
plotter.view_xy()
plotter.subplot(0, 1)
plotter.add_mesh(multiscale_bunny.at(ratio=0.1).to_pyvista())
plotter.add_text(f"N_points={multiscale_bunny.at(ratio=0.1).n_points}")
plotter.view_xy()
plotter.subplot(0, 2)
plotter.add_mesh(multiscale_bunny.at(ratio=0.01).to_pyvista())
plotter.add_text(f"N_points={multiscale_bunny.at(ratio=0.01).n_points}")
plotter.view_xy()
plotter.subplot(0, 3)
plotter.add_mesh(multiscale_bunny.at(ratio=0.005).to_pyvista())
plotter.add_text(f"N_points={multiscale_bunny.at(ratio=0.005).n_points}")
plotter.view_xy()
plotter.show()

Static Scene

Interactive Scene