Coloring of the mesh after boolean filter

[adelka-m]

Hi everyone,
I was wondering, what is actually the output from the boolean operators? Is says it is vtkmodules.vtkCommonDataModel.vtkPolyData as every other mesh, but every other mesh can be colored with the actor when rendering. If you try to render the result of your boolean filter, then it always has these color and you cannot set the color of the actor as you would normally do.

This code works for a data=cylinder from vtkCylinderSource, but not for data=unitedMesh with the boolean filter.

renderer = vtk.vtkRenderer()
renderWindow = vtk.vtkRenderWindow()
renderWindowInteractor = vtk.vtkRenderWindowInteractor()
renderWindowInteractor.SetRenderWindow(renderWindow)
renderWindow.AddRenderer(renderer)
renderer.SetBackground(1, 1, 1) 

mapper = vtk.vtkPolyDataMapper()
mapper.SetInputData(data)
actor = vtk.vtkActor()
actor.SetMapper(mapper)
actor.GetProperty().SetColor(0, 1.0, 1.0)
renderer.AddActor(actor)

renderWindow.Render()
renderWindowInteractor.Start()

Why is it so and how can I make just a "very regular" mesh from the output of the union filter?

---

I have encountered another issue. If I use the vtkConnectivityFilter on this mesh below. It is a cylinder - sphere in the middle of it.

the algorithm says that there are 4 components of the mesh.
Why?

Thanks for your answer!

[adelka-m]

I still don't know, why these filters create multiple components, but I just created a workaroud
Just pass the filtered mesh to the code below.

def createOneComponentMesh(mesh):
    points = mesh.GetPoints()
    cells  = mesh.GetPolys()
    newMesh = vtk.vtkPolyData()
    newMesh.SetPoints(points)
    newMesh.SetPolys(cells)
    return newMesh