VTK中的装配体（vtkAssembly）

#!/usr/bin/env python
import vtk
import math
from vtk.util.colors import *
 
filenames = ["link-1.stl","link-2.stl","link-3.stl"]
dt = 1.0        # degree step in rotation
renWin = vtk.vtkRenderWindow()
actor  = list() # the list of links
joint1 = vtk.vtkAssembly()  
joint2 = vtk.vtkAssembly()
joint3 = vtk.vtkAssembly()

# Customize vtkInteractorStyleTrackballCamera 
class MyInteractor(vtk.vtkInteractorStyleTrackballCamera):
    def __init__(self,parent=None):
        self.AddObserver("CharEvent",self.OnCharEvent)
        self.AddObserver("KeyPressEvent",self.OnKeyPressEvent)

    def OnCharEvent(self,obj,event):
        pass
    
    def OnKeyPressEvent(self,obj,event):
        global angle
        # Get the compound key strokes for the event
        key = self.GetInteractor().GetKeySym()

        # Handle an arrow key
        if(key == "Left"):
            joint1.RotateY(-dt)      
        if(key == "Right"):
            joint1.RotateY(dt)
            
        if(key == "Up"):
            joint2.RotateY(-dt)           
        if(key == "Down"):
            joint2.RotateY(dt)
            
        if(key == "a"):
            joint3.RotateY(-dt)           
        if(key == "d"):
            joint3.RotateY(dt)

        # Ask each renderer owned by this RenderWindow to render its image and synchronize this process
        renWin.Render()
        return
    

def LoadSTL(filename):
    reader = vtk.vtkSTLReader()
    reader.SetFileName(filename)
    mapper = vtk.vtkPolyDataMapper() 
    mapper.SetInputConnection(reader.GetOutputPort())
    actor = vtk.vtkLODActor() 
    actor.SetMapper(mapper)
    return actor  

        
def CreateScene():
    # Create a rendering window and renderer
    ren = vtk.vtkRenderer()
    renWin.AddRenderer(ren)
     
    # Create a renderwindowinteractor
    iren = vtk.vtkRenderWindowInteractor()
    iren.SetRenderWindow(renWin)
    style = MyInteractor()
    style.SetDefaultRenderer(ren)
    iren.SetInteractorStyle(style)
    
    for id, file in enumerate(filenames):
            actor.append(LoadSTL(file))
            r = vtk.vtkMath.Random(.4, 1.0)
            g = vtk.vtkMath.Random(.4, 1.0)
            b = vtk.vtkMath.Random(.4, 1.0)
            actor[id].GetProperty().SetDiffuseColor(r, g, b)
            actor[id].GetProperty().SetDiffuse(.8)
            actor[id].GetProperty().SetSpecular(.5)
            actor[id].GetProperty().SetSpecularColor(1.0,1.0,1.0)
            actor[id].GetProperty().SetSpecularPower(30.0)

    joint1.AddPart(actor[0])
    joint1.AddPart(joint2)
    joint2.AddPart(actor[1])
    joint2.AddPart(joint3)
    joint3.AddPart(actor[2])

    joint2.SetOrigin(100, 0, 0)  # initial elbow joint position
    joint3.SetOrigin(200, 0, 0)  # initial wrist joint position

    ren.AddActor(joint1)

　　# Set background color
    ren.GradientBackgroundOn()
    ren.SetBackground(.1, .1, .1)
    ren.SetBackground2(0.8,0.8,0.8)

    # Set window size
    renWin.SetSize(600, 600)
    
    # Enable user interface interactor
    iren.Initialize()
    iren.Start()
    
    
if __name__ == "__main__":
    CreateScene()