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MultipleRenderWindows

vtk-examples/Python/Visualization/MultipleRenderWindows


Description

This example creates four render windows. Three of the windows will close individually and closing one window will close all the others. Guess which one!

You can also press 'q' or 'e' to close a window.

If the parameter 's' (C++) or '-s (Python) is specified, then updating the camera position in one window will also update the position in the other windows. Pressing 'q' or 'e' closes all windows. Note that in this mode you must use 'q' or 'e' to close the windows.

Note

The image you see here is the test image. When you run this program you will see an image similar to MultipleViewports however each object will be in a separate window.

Other languages

See (Cxx)

Question

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

Code

MultipleRenderWindows.py

import vtk


def get_program_parameters():
    import argparse
    description = 'Display multiple render windows.'
    epilogue = '''
    '''
    parser = argparse.ArgumentParser(description=description, epilog=epilogue,
                                     formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('-s', default=False, action='store_true',
                        help='Simultaneous camera position updating.')
    args = parser.parse_args()
    return args.s


def main():
    simultaneous_update = get_program_parameters()

    colors = vtk.vtkNamedColors()
    # Have some fun with colors
    ren_bkg = ['AliceBlue', 'GhostWhite', 'WhiteSmoke', 'Seashell']
    actor_color = ['Bisque', 'RosyBrown', 'Goldenrod', 'Chocolate']

    # Window sizes and spacing.
    width = 300
    height = 300
    # Add extra space around each window.
    dx = 20
    dy = 40
    w = width + dx
    h = height + dy

    interactors = list()
    running = [True, True, True, True]

    camera = None
    sources = get_sources()

    kpis = list()
    for i in range(0, 4):
        ren_win = vtk.vtkRenderWindow()
        ren_win.SetSize(width, height)

        renderer = vtk.vtkRenderer()

        # Share the camera between viewports.
        if i == 0:
            camera = renderer.GetActiveCamera()
            camera.Azimuth(30)
            camera.Elevation(30)
        else:
            renderer.SetActiveCamera(camera)

        ren_win.AddRenderer(renderer)

        iren = vtk.vtkRenderWindowInteractor()

        interactors.append(iren)

        iren.SetRenderWindow(ren_win)
        ren_win.Render()
        ren_win.SetWindowName('MultipleRenderWindows {:d}'.format(i))
        ren_win.SetPosition((i % 2) * w, h - (i // 2) * h)

        # Create a mapper and actor.
        mapper = vtk.vtkPolyDataMapper()
        mapper.SetInputConnection(sources[i].GetOutputPort())

        actor = vtk.vtkActor()
        actor.SetMapper(mapper)
        actor.GetProperty().SetColor(colors.GetColor3d(actor_color[i]))

        renderer.AddActor(actor)
        renderer.SetBackground(colors.GetColor3d(ren_bkg[i]))

        renderer.ResetCamera()

        running[i] = True
        kpis.append(KeyPressInteractorStyle(parent=iren))
        interactors[i].SetInteractorStyle(kpis[i])
        kpis[i].status = running[i]

    if simultaneous_update:
        interactors[0].Initialize()
        while all(x is True for x in running):
            for i in range(0, 4):
                running[i] = kpis[i].status
                if running[i]:
                    interactors[i].ProcessEvents()
                    interactors[i].Render()
                else:
                    interactors[i].TerminateApp()
                    print('Window', i, 'has stopped running.')
    else:
        interactors[0].Start()


def get_sources():
    sources = list()

    # Create a sphere
    sphere = vtk.vtkSphereSource()
    sphere.SetCenter(0.0, 0.0, 0.0)
    sphere.Update()
    sources.append(sphere)
    # Create a cone
    cone = vtk.vtkConeSource()
    cone.SetCenter(0.0, 0.0, 0.0)
    cone.SetDirection(0, 1, 0)
    cone.Update()
    sources.append(cone)
    # Create a cube
    cube = vtk.vtkCubeSource()
    cube.SetCenter(0.0, 0.0, 0.0)
    cube.Update()
    sources.append(cube)
    # Create a cylinder
    cylinder = vtk.vtkCylinderSource()
    cylinder.SetCenter(0.0, 0.0, 0.0)
    cylinder.Update()
    sources.append(cylinder)

    return sources


class KeyPressInteractorStyle(vtk.vtkInteractorStyleTrackballCamera):

    def __init__(self, parent=None, status=True):
        self.parent = vtk.vtkRenderWindowInteractor()
        self.status = status
        if parent is not None:
            self.parent = parent

        self.AddObserver('KeyPressEvent', self.key_press_event)

    def key_press_event(self, obj, event):
        key = self.parent.GetKeySym().lower()
        if key == 'e' or key == 'q':
            self.status = False
        return


if __name__ == '__main__':
    main()