可视化中不需要的切割问题

Question

我是VTK的新手

当我尝试可视化一个球体，并在sphere.SetCenter（0.0，0.0，z_值）中调整z值时，我只能可视化切割球体

我猜有一个可视框（：立方体）。如何扩展我的ViewCube

half sphere

z_value = -1.0

ren = vtk.vtkRenderer()    
    
sphere = vtk.vtkSphere()
sphere.SetCenter(0.0, 0.0, z_value)
sphere.SetRadius(0.1)

# The sample function generates a distance function from the implicit
# function. This is then contoured to get a polygonal surface.
sample = vtk.vtkSampleFunction()
sample.SetImplicitFunction(sphere)
#sample.SetModelBounds(-100.0, 100.0, -100.0, 100.0, -100.0, 100.0)
#sample.SetSampleDimensions(20, 20, 20)
sample.ComputeNormalsOff()

# contour
surface = vtk.vtkContourFilter()
surface.SetInputConnection(sample.GetOutputPort())
surface.SetValue(0, 0.0)

# mapper
mapper = vtk.vtkPolyDataMapper()
mapper.SetInputConnection(surface.GetOutputPort())
mapper.ScalarVisibilityOff()
actor = vtk.vtkActor()
actor.SetMapper(mapper)
actor.GetProperty().EdgeVisibilityOn()
actor.GetProperty().SetEdgeColor(.2, .2, .5)

# A renderer and render window
ren = vtk.vtkRenderer()
ren.SetBackground(0, 0, 0)

# add the actor
ren.AddActor(actor)

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

# This allows the interactor to initalize itself. It has to be
# called before an event loop.
iren.Initialize()

# We'll zoom in a little by accessing the camera and invoking a "Zoom"
# method on it.
ren.ResetCamera()
#ren.GetActiveCamera().Zoom(1.5)
renWin.Render()

# Start the event loop.
iren.Start()

Answer 1

要修复脚本，应该取消对sample.SetModelBounds()行的注释，并设置球体的实际边界，即

sample.SetModelBounds(centerX - radius, centerX + radius, centerY - radius, centerY + radius, centerZ - radius, centerZ + radius,)

也就是说，如果您只想显示一个球体，那么最好使用vtkSphereSource。因此，可以通过以下方式替换球体采样轮廓零件：

sphere = vtk.vtkSphereSource()
sphere.SetCenter(0.0, 0.0, z_value)
sphere.SetRadius(0.1)
sphere.Update()

及以下 mapper.SetInputConnection(sphere.GetOutputPort())