pyvista.PolyDataFilters.triangulate_contours

PolyDataFilters.triangulate_contours(display_errors=False, progress_bar=False)

Triangulate and fill all 2D contours to create polygons.

Added in version 0.44.0.

This filter will generate triangles to fill all of the 2D contours in its input. The input to the filter is a set of lines (not polylines) which when joined form loops. The contours may be concave, and may even contain holes i.e. a contour may contain an internal contour that is wound in the opposite direction (as compared to the outer polygon normal) to indicate that it is a hole.

Note

This filter will assume that the input polygons lie in the same plane and will not perform any projection or transformation of the input data. You may need to project your data to a plane before using this filter.

Warning

The triangulation of is done in O(n) time for simple convex inputs, but for non-convex inputs the worst-case time is O(n^2*m^2) where n is the number of points and m is the number of holes. The best triangulation algorithms, in contrast, are O(n log n). The resulting triangles may be quite narrow, the algorithm does not attempt to produce high-quality triangles.

Parameters:

display_errorsbool, default: False

Generate errors when the triangulation fails. Note that triangulation failures are often minor, because they involve tiny triangles that are too small to see.

progress_barbool, default: False

Display a progress bar to indicate progress.

Returns:

pyvista.PolyData

Triangulated mesh with the filled contours.

Examples

Create banded contour and fill.

>>> import pyvista as pv
>>> from pyvista import examples
>>> image = examples.download_st_helens()
>>> contours = image.contour([1302.3334, 1922.6666])
>>> filled = contours.triangulate_contours()

>>> pl = pv.Plotter(shape=(1, 2))
>>> _ = pl.add_mesh(image, show_scalar_bar=False)
>>> _ = pl.add_mesh(contours, color='black')
>>> pl.subplot(0, 1)
>>> _ = pl.add_mesh(contours, color='black')
>>> _ = pl.add_mesh(filled, color='red')
>>> pl.link_views()
>>> pl.view_xy()
>>> pl.show()

Static Scene

Interactive Scene