Rotations

VTKExamples/Python/Rendering/Rotations


Description

Rotations of a cow about her axes. In this model, the x axis is from the left to right; the y axis is from bottom to top; and the z axis emerges from the image. The camera location is the same in all four images.

Code

Rotations.py

#!/usr/local/bin/python

import vtk


def main():
    """
        To match the illustrations in VTKTextbook.pdf, use BkgColor as the background and
          Wheat as the cow colour.
        Also comment out the lines:
          modelActor->GetProperty()->SetSpecular(.6);
          modelActor->GetProperty()->SetSpecularPower(30);
        and use cow.g as the input data.

    """
    file_name, figure, book_color = get_program_parameters()
    rotate(file_name, figure, book_color)


def rotate(file_name, figure, book_color):
    """"
    This is where we do the rotations.

    """
    # Create renderer stuff
    #
    colors = vtk.vtkNamedColors()
    # Set the background color.
    colors.SetColor("BkgColor", [26, 51, 102, 255])
    # colors.SetColor("BkgColor", [60, 93, 144, 255])

    ren1 = vtk.vtkRenderer()
    renWin = vtk.vtkRenderWindow()
    renWin.AddRenderer(ren1)

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

    # Create the pipeline.
    #
    polyData = ReadPolyData(file_name)

    modelMapper = vtk.vtkPolyDataMapper()
    modelMapper.SetInputData(polyData)

    modelActor = vtk.vtkActor()
    modelActor.SetMapper(modelMapper)
    if book_color:
        modelActor.GetProperty().SetDiffuseColor(colors.GetColor3d("Wheat"))
    else:
        modelActor.GetProperty().SetDiffuseColor(colors.GetColor3d("Crimson"))
        modelActor.GetProperty().SetSpecular(.6)
        modelActor.GetProperty().SetSpecularPower(30)

    modelAxesSource = vtk.vtkAxes()
    modelAxesSource.SetScaleFactor(10)
    modelAxesSource.SetOrigin(0, 0, 0)

    modelAxesMapper = vtk.vtkPolyDataMapper()
    modelAxesMapper.SetInputConnection(modelAxesSource.GetOutputPort())

    modelAxes = vtk.vtkActor()
    modelAxes.SetMapper(modelAxesMapper)

    ren1.AddActor(modelAxes)
    modelAxes.VisibilityOff()

    # Add the actors to the renderer, set the background and size.
    #
    ren1.AddActor(modelActor)
    if book_color:
        ren1.SetBackground(colors.GetColor3d("BkgColor"))
    else:
        ren1.SetBackground(colors.GetColor3d("Silver"))
    renWin.SetSize(640, 480)
    ren1.ResetCamera()
    ren1.GetActiveCamera().Azimuth(0)
    ren1.GetActiveCamera().SetClippingRange(.1, 1000.0)

    modelAxes.VisibilityOn()

    renWin.Render()
    renWin.Render()

    if figure == 1:
        RotateX(renWin, modelActor)
    elif figure == 2:
        RotateY(renWin, modelActor)
    elif figure == 3:
        RotateZ(renWin, modelActor)
    else:
        RotateXY(renWin, modelActor)

    renWin.EraseOff()
    iren.Start()


def get_program_parameters():
    import argparse
    description = 'Perform rotations about the X, Y, Z and X then Y axes.'
    epilogue = '''
        Perform rotations about the X, Y, Z and X then Y axes.
   '''
    parser = argparse.ArgumentParser(description=description, epilog=epilogue)
    parser.add_argument('filename', help='The file cow.obj.')
    parser.add_argument('figure', default=0, type=int, nargs='?',
                        help='The particular rotation that you want to view.')
    parser.add_argument('book_color', default=False, type=bool, nargs='?',
                        help='If True then the vtk textbook colors are used.')
    args = parser.parse_args()
    return args.filename, args.figure, args.book_color


def RotateX(renWin, actor):
    actor.SetOrientation(0, 0, 0)
    renWin.Render()
    renWin.Render()
    renWin.EraseOff()

    for i in range(0, 6):
        actor.RotateX(60)
        renWin.Render()
        renWin.Render()
    renWin.EraseOn()


def RotateY(renWin, actor):
    actor.SetOrientation(0, 0, 0)
    renWin.Render()
    renWin.EraseOff()

    for i in range(0, 6):
        actor.RotateY(60)
        renWin.Render()
        renWin.Render()
    renWin.EraseOn()


def RotateZ(renWin, actor):
    actor.SetOrientation(0, 0, 0)
    renWin.Render()
    renWin.EraseOff()

    for i in range(0, 6):
        actor.RotateZ(60)
        renWin.Render()
        renWin.Render()
    renWin.EraseOn()


def RotateXY(renWin, actor):
    actor.SetOrientation(0, 0, 0)
    actor.RotateX(60)
    renWin.Render()
    renWin.Render()
    renWin.EraseOff()

    for i in range(0, 6):
        actor.RotateY(60)
        renWin.Render()
        renWin.Render()
    renWin.EraseOn()


def ReadPolyData(file_name):
    import os
    path, extension = os.path.splitext(file_name)
    extension = extension.lower()
    if extension == ".ply":
        reader = vtk.vtkPLYReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".vtp":
        reader = vtk.vtkXMLpoly_dataReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".obj":
        reader = vtk.vtkOBJReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".stl":
        reader = vtk.vtkSTLReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".vtk":
        reader = vtk.vtkpoly_dataReader()
        reader.SetFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    elif extension == ".g":
        reader = vtk.vtkBYUReader()
        reader.SetGeometryFileName(file_name)
        reader.Update()
        poly_data = reader.GetOutput()
    else:
        # Return a sphere if the extension is unknown.
        source = vtk.vtkSphereSource()
        source.Update()
        poly_data = source.GetOutput()
    return poly_data


if __name__ == '__main__':
    main()