AnimateVectors
VTKExamples/Python/Texture/AnimateVectors
Description¶
Texture maps can be animated as a function of time. By choosing a texture map whose intensity varies monotonically from dark to light, and then “moving” the texture along an object,the object appears to crawl in the direction of the texture map motion. We can use this technique to add apparent motion to things like hedgehogs to show vector magnitude. This example uses texture map animation to simulate vector field motion.
Cite
See B. Yamrom and K. M. Martin. Vector Field Animation with Texture Maps. IEEE Computer Graphics and Applications. 15(2):22–24, 1995 for background.
Other Languages
See (Cxx)
Question
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Code¶
AnimateVectors.py
#!/usr/bin/env python import vtk def main(): fileNames = [""] * 2 fileNames[0], fileNames[1] = get_program_parameters() # Generate the other vecAnim file names. There are 8 of them. tmpFn = fileNames[1][:-5] for i in range(2, 9): fileNames.append(tmpFn + str(i) + ".vtk") colors = vtk.vtkNamedColors() # Setup the render window, renderer, and interactor. renderer = vtk.vtkRenderer() renderWindow = vtk.vtkRenderWindow() renderWindow.AddRenderer(renderer) interactor = vtk.vtkRenderWindowInteractor() interactor.SetRenderWindow(renderWindow) # Read the data. # # Create the pipeline. # reader = vtk.vtkStructuredPointsReader() reader.SetFileName(fileNames[0]) threshold = vtk.vtkThresholdPoints() threshold.SetInputConnection(reader.GetOutputPort()) threshold.ThresholdByUpper(200) line = vtk.vtkLineSource() line.SetResolution(1) lines = vtk.vtkGlyph3D() lines.SetInputConnection(threshold.GetOutputPort()) lines.SetSourceConnection(line.GetOutputPort()) lines.SetScaleFactor(0.005) lines.SetScaleModeToScaleByScalar() lines.Update() vectorMapper = vtk.vtkPolyDataMapper() vectorMapper.SetInputConnection(lines.GetOutputPort()) vectorMapper.SetScalarRange(lines.GetOutput().GetScalarRange()) vectorActor = vtk.vtkActor() vectorActor.SetMapper(vectorMapper) vectorActor.GetProperty().SetOpacity(0.99) vectorActor.GetProperty().SetLineWidth(1.5) # Outline outline = vtk.vtkOutlineFilter() outline.SetInputConnection(reader.GetOutputPort()) outlineMapper = vtk.vtkPolyDataMapper() outlineMapper.SetInputConnection(outline.GetOutputPort()) outlineActor = vtk.vtkActor() outlineActor.SetMapper(outlineMapper) outlineActor.GetProperty().SetColor(colors.GetColor3d("Black")) # Texture maps. textureMaps = list() for i in range(2, len(fileNames)): tmap = vtk.vtkStructuredPointsReader() tmap.SetFileName(fileNames[i]) texture = vtk.vtkTexture() texture.SetInputConnection(tmap.GetOutputPort()) texture.InterpolateOff() texture.RepeatOff() textureMaps.append(texture) vectorActor.SetTexture(textureMaps[0]) # Add the actors to the renderer, set the background and size. # renderer.AddActor(vectorActor) renderer.AddActor(outlineActor) cam1 = vtk.vtkCamera() cam1.SetClippingRange(17.4043, 870.216) cam1.SetFocalPoint(136.71, 104.025, 23) cam1.SetPosition(204.747, 258.939, 63.7925) cam1.SetViewUp(-0.102647, -0.210897, 0.972104) cam1.Zoom(1.5) renderer.SetActiveCamera(cam1) renderer.SetBackground(colors.GetColor3d("Wheat")) renderWindow.SetSize(640, 480) # Go into a loop. for j in range(0, 100): for i in range(0, len(textureMaps)): vectorActor.SetTexture(textureMaps[i]) renderWindow.Render() interactor.Start() def get_program_parameters(): import argparse description = 'Texture maps can be animated as a function of time.' epilogue = ''' This example uses texture map animation to simulate vector field motion. ''' parser = argparse.ArgumentParser(description=description, epilog=epilogue, formatter_class=argparse.RawDescriptionHelpFormatter) parser.add_argument('filename1', help='carotid.vtk.') parser.add_argument('filename2', help='vecAnim1.vtk.') args = parser.parse_args() return args.filename1, args.filename2 if __name__ == '__main__': main()