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# Planes

VTKEx/Python/GeometricObjects/Planes

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See (Cxx), (CSharp)

Question

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### Code

Planes.py

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

    import vtk

    def main():
        colors = vtk.vtkNamedColors()

        planes = list()
        titles = list()

        # Using frustum planes.
        titles.append('Using frustum planes')
        camera = vtk.vtkCamera()
        planesArray = [0] * 24
        camera.GetFrustumPlanes(1, planesArray)
        planes.append(vtk.vtkPlanes())
        planes[0].SetFrustumPlanes(planesArray)

        # Using bounds.
        titles.append('Using bounds')
        sphereSource = vtk.vtkSphereSource()
        sphereSource.Update()
        bounds = [0] * 6
        sphereSource.GetOutput().GetBounds(bounds)
        planes.append(vtk.vtkPlanes())
        planes[1].SetBounds(bounds)

        # At this point we have the planes created by both of the methods above.
        # You can do whatever you want with them.

        # For visualisation we will produce an n-sided convex hull
        # and visualise it.

        # Create a common text property.
        textProperty = vtk.vtkTextProperty()
        textProperty.SetFontSize(16)
        textProperty.SetJustificationToCentered()

        renWin = vtk.vtkRenderWindow()
        renWin.SetSize(600, 600)
        renWin.SetWindowName("Planes")

        iRen = vtk.vtkRenderWindowInteractor()
        iRen.SetRenderWindow(renWin)

        hulls = list()
        pds = list()
        mappers = list()
        actors = list()
        renderers = list()
        textMappers = list()
        textActors = list()
        for i in range(0, len(planes)):
            hulls.append(vtk.vtkHull())
            hulls[i].SetPlanes(planes[i])

            pds.append(vtk.vtkPolyData())

            # To generate the convex hull we supply a vtkPolyData object and a bounding box.
            # We define the bounding box to be where we expect the resulting polyhedron to lie.
            # Make it a generous fit as it is only used to create the initial
            # polygons that are eventually clipped.
            hulls[i].GenerateHull(pds[i], -200, 200, -200, 200, -200, 200)

            mappers.append(vtk.vtkPolyDataMapper())
            mappers[i].SetInputData(pds[i])

            actors.append(vtk.vtkActor())
            actors[i].SetMapper(mappers[i])
            actors[i].GetProperty().SetColor(colors.GetColor3d("Moccasin"))
            actors[i].GetProperty().SetSpecular(0.8)
            actors[i].GetProperty().SetSpecularPower(30)

            renderers.append(vtk.vtkRenderer())
            renderers[i].AddActor(actors[i])

            textMappers.append(vtk.vtkTextMapper())
            textMappers[i].SetInput(titles[i])
            textMappers[i].SetTextProperty(textProperty)

            textActors.append(vtk.vtkActor2D())
            textActors[i].SetMapper(textMappers[i])
            textActors[i].SetPosition(100, 10)
            renderers[i].AddViewProp(textActors[i])

            renWin.AddRenderer(renderers[i])

        # Setup the viewports
        xGridDimensions = 2
        yGridDimensions = 1
        rendererSize = 300
        renWin.SetSize(rendererSize * xGridDimensions, rendererSize * yGridDimensions)
        for row in range(0, yGridDimensions):
            for col in range(0, xGridDimensions):
                index = row * xGridDimensions + col

                # (xmin, ymin, xmax, ymax)
                viewport = [float(col) / xGridDimensions,
                            float(yGridDimensions - (row + 1)) / yGridDimensions,
                            float(col + 1) / xGridDimensions,
                            float(yGridDimensions - row) / yGridDimensions]

                if index > (len(actors) - 1):
                    # Add a renderer even if there is no actor.
                    # This makes the render window background all the same color.
                    ren = vtk.vtkRenderer()
                    ren.SetBackground(colors.GetColor3d("DarkSlateGray"))
                    ren.SetViewport(viewport)
                    renWin.AddRenderer(ren)
                    continue

                renderers[index].SetViewport(viewport)
                renderers[index].SetBackground(colors.GetColor3d("DarkSlateGray"))
                renderers[index].ResetCamera()
                renderers[index].GetActiveCamera().Azimuth(30)
                renderers[index].GetActiveCamera().Elevation(-30)
                renderers[index].ResetCameraClippingRange()

        iRen.Initialize()
        renWin.Render()
        iRen.Start()

    if __name__ == '__main__':
        main()