Extrude Rotation

Sweep polygonal data creating “skirt” from free edges and lines, and lines from vertices.

This takes polygonal data as input and generates polygonal data on output. The input dataset is swept around the z-axis to create new polygonal primitives. These primitives form a “skirt” or swept surface. For example, sweeping a line results in a cylindrical shell, and sweeping a circle creates a torus.

import numpy as np

import pyvista

# create a line and rotate it about the Z-axis
resolution = 10
line = pyvista.Line(pointa=(0, 0, 0), pointb=(1, 0, 0), resolution=2)
poly = line.extrude_rotate(resolution=resolution)
poly

Out:

/home/alex/python/pyvista/pyvista/core/filters/poly_data.py:2907: PyvistaFutureWarning: The default value of the ``capping`` keyword argument will change in a future version to ``True`` to match the behavior of VTK. We recommend passing the keyword explicitly to prevent future surprises.
  warnings.warn(

Header	Data Arrays
PolyData Information N Cells 2 N Points 33 X Bounds -1.000e+00, 1.000e+00 Y Bounds -9.511e-01, 9.511e-01 Z Bounds 0.000e+00, 0.000e+00 N Arrays 2	Name Field Type N Comp Min Max Texture Coordinates Points float32 2 0.000e+00 1.000e+00 Distance Points float64 1 0.000e+00 1.000e+00

Plot the extruded line

plotter = pyvista.Plotter(shape=(2, 1))
plotter.subplot(0, 0)
plotter.add_text("Line", font_size=24)
plotter.add_mesh(line, color="tan", show_edges=True)
plotter.add_mesh(
    pyvista.PolyData(line.points),
    color="red",
    point_size=10,
    render_points_as_spheres=True,
)
plotter.subplot(1, 0)
plotter.add_text("Extrude Rotated Line", font_size=24)
plotter.add_mesh(poly, color="tan", show_edges=True)
plotter.add_mesh(
    pyvista.PolyData(poly.points),
    color="red",
    point_size=10,
    render_points_as_spheres=True,
)

plotter.show(cpos="xy")

Create a spring

# Create the spring profile (a circle).
plotter = pyvista.Plotter()

vertices = np.array(
    [
        [1.0, 0.0, 0.0],
        [1.0732, 0.0, -0.1768],
        [1.25, 0.0, -0.25],
        [1.4268, 0.0, -0.1768],
        [1.5, 0.0, 0.00],
        [1.4268, 0.0, 0.1768],
        [1.25, 0.0, 0.25],
        [1.0732, 0.0, 0.1768],
    ]
)
faces = np.hstack([[8, 0, 1, 2, 3, 4, 5, 6, 7]])
profile = pyvista.PolyData(vertices, faces)

# Extrude the profile to make a spring.
spring = profile.extrude_rotate(resolution=360, translation=6.0, dradius=1.0, angle=2160.0)
plotter.add_text("Spring", font_size=24)
plotter.add_mesh(spring, color="tan", show_edges=True)

plotter.show(cpos="zx")

Out:

/home/alex/python/pyvista/pyvista/core/filters/poly_data.py:2907: PyvistaFutureWarning: The default value of the ``capping`` keyword argument will change in a future version to ``True`` to match the behavior of VTK. We recommend passing the keyword explicitly to prevent future surprises.
  warnings.warn(