在两个vtkPolyData对象之间绘制最接近的向量？

Question

我正在使用vtk来确定两个polydata对象之间的最小距离。我使用vtkDistancePolyDataFilter来确定最小距离，但是如何确定每个对象上定义这个最小结果的关联x、y、z点呢？在

下面的最小示例根据到圆柱体的距离对立方体进行着色；我希望在每个vtkPolyData对象上最近的点之间绘制一个vtkLine。vtkDistancePolyDataFilter的结果似乎包括立方体对象的单元格、法线和距离，但我不知道如何轻松地找出其中哪一个与最小距离相关，也不知道如何与圆柱体上的点相关。在

编辑：我不确定vtkDistancePolyDataFilter是否正确计算最小距离-它似乎只进行顶点-顶点交互。在

import vtk

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

cube = vtk.vtkCubeSource()
cube.SetCenter (1.2, 0.3, 0.4);

transform = vtk.vtkTransform()
transform.RotateX(45)
transform.RotateY(45)
transform.Translate((1.2,0.2,0))

tf = vtk.vtkTransformPolyDataFilter()
tf.SetInput(cube.GetOutput())
tf.SetTransform(transform)
tf.Update()

cubeMapper = vtk.vtkPolyDataMapper()
cubeMapper.SetInput(tf.GetOutput())
cubeActor = vtk.vtkActor()
cubeActor.SetMapper(cubeMapper)

#Create Cylinder
cylinder = vtk.vtkCylinderSource()
cylinder.SetHeight(2)
cylinderMapper = vtk.vtkPolyDataMapper()
cylinderMapper.SetInput(cylinder.GetOutput())
cylinderActor = vtk.vtkActor()
cylinderActor.SetMapper(cylinderMapper)

#Determine distance btwn Cylinder and Cube
distfilt = vtk.vtkDistancePolyDataFilter()
distfilt.SetInputConnection(1, tf.GetOutputPort())
distfilt.SetInputConnection(0, cylinder.GetOutputPort())
distfilt.Update()

#Color the cube based on distance to cylinder
distmapper = vtk.vtkPolyDataMapper()
distmapper.SetInputConnection(distfilt.GetOutputPort(1))
distmapper.SetScalarRange( \
    distfilt.GetOutput().GetPointData().GetScalars().GetRange()[0],
    distfilt.GetOutput().GetPointData().GetScalars().GetRange()[1],)

distactor = vtk.vtkActor()
distactor.SetMapper(distmapper)

distarray = distfilt.GetOutput().GetPointData().GetScalars()
for i in range(24):
    print distarray.GetValue(i)
    # Minimum distance is the lowest of these results, but what are the
    # Corresponding points on the cylinder and cube?

scalarBar = vtk.vtkScalarBarActor()
scalarBar.SetLookupTable(distmapper.GetLookupTable())
scalarBar.SetTitle("Distance")
scalarBar.SetNumberOfLabels(5)

ren.AddActor(cubeActor)
ren.AddActor(cylinderActor)
ren.AddActor(distactor)
ren.AddActor2D(scalarBar)

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

Answer 1

这不能直接用VTK完成-需要物理/运动学/碰撞库。我现在要和Bullet一起工作。在