import vtk

class KeyPressInteractorStyle(vtk.vtkInteractorStyleTrackballCamera):

    def __init__(self,parent=None):

        self.parent = vtk.vtkRenderWindowInteractor()

        if(parent is not None):

            self.parent = parent

        self.AddObserver("KeyPressEvent",self.keyPress)

    def keyPress(self,obj,event):

        key = self.parent.GetKeySym()

        if key == 'Up':

            #产生随机颜色

            r = vtk.vtkMath.Random(., 1.0)

            g = vtk.vtkMath.Random(., 1.0)

            b = vtk.vtkMath.Random(., 1.0)

            actor.GetProperty().SetColor(r, g, b)

            #下面这一行是关键，实现了actor的更新

            renWin.Render()

#在此处修改几何类型

cube = vtk.vtkCubeSource()

mapper = vtk.vtkPolyDataMapper()

mapper.SetInputConnection(cube.GetOutputPort())

actor = vtk.vtkActor()

actor.SetMapper(mapper)

#修改actor初始颜色

actor.GetProperty().SetColor(1.0, 1.0, 1.0)

#修改actor初始状态旋转角度

actor.RotateX(30.0)

actor.RotateY(-45.0)

ren = vtk.vtkRenderer()

renWin = vtk.vtkRenderWindow()

renWin.AddRenderer(ren)

iren = vtk.vtkRenderWindowInteractor()

iren.SetRenderWindow(renWin)

iren.SetInteractorStyle(KeyPressInteractorStyle(parent = iren))

ren.AddActor(actor)

#修改背景颜色

ren.SetBackground(0.1, 0.2, 0.3)

#修改窗口大小

renWin.SetSize(, )

iren.Initialize()

ren.ResetCamera()

ren.GetActiveCamera().Zoom(1.5)

renWin.Render()

iren.Start()