pythonbooleanvtk

Convert STL object to VTK geometry in python


I am wanting to do Boolean operations on STL files with geometric primitives from the VTK library.

My problem is converting the STL geometry to something that the VTK Boolean objects will except.

I tried the following...

import vtk

filename = 'gyroid.stl' 
reader = vtk.vtkSTLReader()
reader.SetFileName(filename)
mapper = vtk.vtkPolyDataMapper()
mapper.SetInputConnection(reader.GetOutputPort())
gyroid = vtk.vtkActor()
gyroid.SetMapper(mapper)

sphere = vtk.vtkSphere()
sphere.SetRadius(30)
sphere.SetCenter(0, 0, 0)

boolean = vtk.vtkImplicitBoolean()
boolean.SetOperationTypeToIntersection()
boolean.AddFunction(gyroid)
boolean.AddFunction(sphere)

But get the following error...

File "D:\Python codes\VTK\untitled8.py", line 29, in <module>
    boolean.AddFunction(gyroid)

TypeError: AddFunction argument %Id: %V

It throws the same error if I replace gyroid with mapper

How do I convert the STL mesh into something useable by VTK? Or cant I do this & need to look elsewhere?


Solution

  • The problem is not about converting STL in VTK but about how to use VTK API :)

    vtkImplicitBoolean works on implicits function, i.e. classes that can generate data, such as the vtkSphere. See here for doc and here for usage

    As you have a loaded dataset, you cannot use this. Instead, use vtkBooleanOperationPolyDataFilter and generate a sphere with the vtkSphereSource. Here and here for examples.

    Example

    sphere = vtk.vtkSphereSource()
    booleanOperation = vtk.vtkBooleanOperationPolyDataFilter()
    booleanOperation.SetOperationToIntersection()
    booleanOperation.SetInputConnection(0, reader.GetOutputPort())
    booleanOperation.SetInputConnection(1, sphere.GetOutputPort())