EllipticalCylinder

Description¶

The example creates an elliptical cross-section and stores it in a vtkPolyData. Then, the vtkLinearExtrusionFilter creates an elliptical cylinder by extruding the vtkPolyLine along a vector. The example sets the backface property of the vtkActor to show the front and back face of the cylinder.

Seealso

EllipticalCylinderDemo to see the vtkPolyLine and the vector represented as an oriented

arrow.

Other languages

See (Cxx), (Java)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code¶

EllipticalCylinder.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import math

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkCommonCore import (
    vtkMath,
    vtkPoints
)
from vtkmodules.vtkCommonDataModel import (
    vtkCellArray,
    vtkPolyData,
    vtkPolyLine
)
from vtkmodules.vtkFiltersModeling import vtkLinearExtrusionFilter
from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkCamera,
    vtkPolyDataMapper,
    vtkProperty,
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer
)


def main():
    colors = vtkNamedColors()

    angle = 0
    r1 = 50
    r2 = 30
    centerX = 10.0
    centerY = 5.0

    points = vtkPoints()
    idx = 0
    while angle <= 2.0 * vtkMath.Pi() + (vtkMath.Pi() / 60.0):
        points.InsertNextPoint(r1 * math.cos(angle) + centerX,
                               r2 * math.sin(angle) + centerY,
                               0.0)
        angle = angle + (vtkMath.Pi() / 60.0)
        idx += 1

    line = vtkPolyLine()
    line.GetPointIds().SetNumberOfIds(idx)
    for i in range(0, idx):
        line.GetPointIds().SetId(i, i)

    lines = vtkCellArray()
    lines.InsertNextCell(line)

    polyData = vtkPolyData()
    polyData.SetPoints(points)
    polyData.SetLines(lines)

    extrude = vtkLinearExtrusionFilter()
    extrude.SetInputData(polyData)
    extrude.SetExtrusionTypeToNormalExtrusion()
    extrude.SetVector(0, 0, 100.0)
    extrude.Update()

    lineMapper = vtkPolyDataMapper()
    lineMapper.SetInputData(polyData)

    lineActor = vtkActor()
    lineActor.SetMapper(lineMapper)
    lineActor.GetProperty().SetColor(colors.GetColor3d("Peacock"))

    mapper = vtkPolyDataMapper()
    mapper.SetInputConnection(extrude.GetOutputPort())

    back = vtkProperty()
    back.SetColor(colors.GetColor3d("Tomato"))

    actor = vtkActor()
    actor.SetMapper(mapper)
    actor.GetProperty().SetColor(colors.GetColor3d("Banana"))
    actor.SetBackfaceProperty(back)

    ren = vtkRenderer()
    ren.SetBackground(colors.GetColor3d("SlateGray"))
    ren.AddActor(actor)
    ren.AddActor(lineActor)

    renWin = vtkRenderWindow()
    renWin.SetWindowName("EllipticalCylinder")
    renWin.AddRenderer(ren)
    renWin.SetSize(600, 600)

    iren = vtkRenderWindowInteractor()
    iren.SetRenderWindow(renWin)

    style = vtkInteractorStyleTrackballCamera()
    iren.SetInteractorStyle(style)

    camera = vtkCamera()
    camera.SetPosition(0, 1, 0)
    camera.SetFocalPoint(0, 0, 0)
    camera.SetViewUp(0, 0, 1)
    camera.Azimuth(30)
    camera.Elevation(30)

    ren.SetActiveCamera(camera)
    ren.ResetCamera()
    ren.ResetCameraClippingRange()

    renWin.Render()
    iren.Start()


if __name__ == '__main__':
    main()