This example introduces the concepts of interaction into the Python environment. A different interaction style (than the default) is defined.
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#!/usr/bin/env python """ ========================================================================= Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen All rights reserved. See Copyright.txt or http://www.kitware.com/Copyright.htm for details. This software is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the above copyright notice for more information. =========================================================================*/ """ # First access the VTK module (and any other needed modules) by importing them. # noinspection PyUnresolvedReferences import vtkmodules.vtkRenderingOpenGL2 from vtkmodules.vtkCommonColor import vtkNamedColors from vtkmodules.vtkFiltersSources import vtkConeSource from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera from vtkmodules.vtkRenderingCore import ( vtkActor, vtkPolyDataMapper, vtkRenderWindow, vtkRenderWindowInteractor, vtkRenderer ) def main(argv): colors = vtkNamedColors() # # Next we create an instance of vtkConeSource and set some of its # properties. The instance of vtkConeSource 'cone' is part of a # visualization pipeline (it is a source process object) it produces data # (output type is vtkPolyData) which other filters may process. # cone = vtkConeSource() cone.SetHeight(3.0) cone.SetRadius(1.0) cone.SetResolution(10) # # In this example we terminate the pipeline with a mapper process object. # (Intermediate filters such as vtkShrinkPolyData could be inserted in # between the source and the mapper.) We create an instance of # vtkPolyDataMapper to map the polygonal data into graphics primitives. We # connect the output of the cone source to the input of this mapper. # coneMapper = vtkPolyDataMapper() coneMapper.SetInputConnection(cone.GetOutputPort()) # # Create an actor to represent the cone. The actor orchestrates rendering # of the mapper's graphics primitives. An actor also refers to properties # via a vtkProperty instance, and includes an internal transformation # matrix. We set this actor's mapper to be coneMapper which we created # above. # coneActor = vtkActor() coneActor.SetMapper(coneMapper) coneActor.GetProperty().SetColor(colors.GetColor3d('Bisque')) # # Create the Renderer and assign actors to it. A renderer is like a # viewport. It is part or all of a window on the screen and it is # responsible for drawing the actors it has. We also set the background # color here. # ren1 = vtkRenderer() ren1.AddActor(coneActor) ren1.SetBackground(colors.GetColor3d('MidnightBlue')) # # Finally we create the render window which will show up on the screen. # We put our renderer into the render window using AddRenderer. We also # set the size to be 300 pixels by 300. # renWin = vtkRenderWindow() renWin.AddRenderer(ren1) renWin.SetSize(300, 300) renWin.SetWindowName('Tutorial_Step5') # # The vtkRenderWindowInteractor class watches for events (e.g., keypress, # mouse) in the vtkRenderWindow. These events are translated into # event invocations that VTK understands (see VTK/Common/vtkCommand.h # for all events that VTK processes). Then observers of these VTK # events can process them as appropriate. iren = vtkRenderWindowInteractor() iren.SetRenderWindow(renWin) # # By default the vtkRenderWindowInteractor instantiates an instance # of vtkInteractorStyle. vtkInteractorStyle translates a set of events # it observes into operations on the camera, actors, and/or properties # in the vtkRenderWindow associated with the vtkRenderWinodwInteractor. # Here we specify a particular interactor style. style = vtkInteractorStyleTrackballCamera() iren.SetInteractorStyle(style) # # Unlike the previous scripts where we performed some operations and then # exited, here we leave an event loop running. The user can use the mouse # and keyboard to perform the operations on the scene according to the # current interaction style. When the user presses the 'e' key, by default # an ExitEvent is invoked by the vtkRenderWindowInteractor which is caught # and drops out of the event loop (triggered by the Start() method that # follows. # iren.Initialize() iren.Start() # # Final note: recall that observers can watch for particular events and # take appropriate action. Pressing 'u' in the render window causes the # vtkRenderWindowInteractor to invoke a UserEvent. This can be caught to # popup a GUI, etc. See the Tcl Cone5.tcl example for an idea of how this # works. if __name__ == '__main__': import sys main(sys.argv)