python - 从 vtkActor 更新 vtkPolyData

Question

我是 VTK 的新手。我正在尝试在 python 中使用 VTK 来使用 vtkBoxWidget 编辑 .STL 文件。我正在读取 .STL 文件，通过在窗口交互器中使用鼠标/拖动，使用 vtkBoxWidget 对其进行编辑，最后我想将新数据写入一个新的 .STL 当按下某个键时。

下面是演示问题的代码:

#!/usr/bin/env python

import vtk
import sys
import os

filename = "file.stl"
# render the data
reader = vtk.vtkSTLReader()
reader.SetFileName(filename)

stlMapper = vtk.vtkPolyDataMapper()
stlMapper.SetInputConnection(reader.GetOutputPort())

# create an actor for our scene

stlActor = vtk.vtkActor()
stlActor.SetMapper(stlMapper)



ren = vtk.vtkRenderer()
renWin = vtk.vtkRenderWindow()
renWin.AddRenderer(ren)
iren = vtk.vtkRenderWindowInteractor()
iren.SetRenderWindow(renWin)

# The box widget observes the events invoked by the render window
# interactor.  These events come from user interaction in the render
# window.
boxWidget = vtk.vtkBoxWidget()
boxWidget.SetInteractor(iren)
boxWidget.SetPlaceFactor(1.25)

# Add the actors to the renderer, set the background and window size.
ren.AddActor(stlActor)
ren.SetBackground(0.1, 0.2, 0.4)
renWin.SetSize(300, 300)

# As the box widget is interacted with, it produces a transformation
# matrix that is set on the actor.
t = vtk.vtkTransform()
def TransformActor(obj, event):
    global t, stlActor
    obj.GetTransform(t)
    stlActor.SetUserTransform(t)

def onKeyPressEvent(self, renderer):
    key = self.GetKeyCode()
    if(key=='l'):
        print stlActor.GetBounds()
        if(os.path.isfile("done.stl")==1):
                    os.remove("done.stl")
        print stlActor.GetMapper().GetInput().GetBounds()
        stlPolyData = stlActor.GetMapper().GetInput()
        writer = vtk.vtkSTLWriter()
        writer.SetFileName("done.stl")
        writer.AddInputDataObject(stlPolyData)
        writer.Write()
# Place the interactor initially. The actor is used to place and scale
# the interactor. An observer is added to the box widget to watch for
# interaction events. This event is captured and used to set the
# transformation matrix of the actor.
boxWidget.SetProp3D(stlActor)
boxWidget.PlaceWidget()
boxWidget.AddObserver("InteractionEvent", TransformActor)
iren.AddObserver('KeyPressEvent', onKeyPressEvent)

iren.Initialize()
renWin.Render()
iren.Start()

问题是我不知道如何更新 vtkPolyData 或将我应用于 vtkActor 的转换传递给 vtkPolyData。在上面的代码中，我在两个打印函数中使用 .GetBounds() 对此进行了测试。最初对象有边界:

(-2.0, 2.0, 0.0, 1.625, -1.5, 1.8125)

更新后，actor Bounds 改变了，但我无法将所有这些属性传递给 vtkPolyData。

(-2.1331110248939638, 2.246371570191821, -1.5743578447908013, 2.5817210301577385, -2.1311284932847796, 2.0695034726591715)
(-2.0, 2.0, 0.0, 1.625, -1.5, 1.8125)

谢谢!

Answer 1

我想我想通了:

def transformPolyData(actor):
    polyData = vtk.vtkPolyData()
    polyData.DeepCopy(actor.GetMapper().GetInput())
    transform = vtk.vtkTransform()
    transform.SetMatrix(actor.GetMatrix())
    fil = vtk.vtkTransformPolyDataFilter()
    fil.SetTransform(transform)
    fil.SetInputDataObject(polyData)
    fil.Update()
    polyData.DeepCopy(fil.GetOutput())
    return polyData;

这会将 polyData 转换为我在保存之前需要的内容。