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BooleanPolyDataFilters

web-test/PythonicAPI/PolyData/BooleanPolyDataFilters

Description

This example uses either the vtkBooleanOperationPolyDataFilter or vtkLoopBooleanPolyDataFilter. These filters work best with "clean" data, so this example first runs vtkTriangleFilter and then vtkCleanPolyData.

The LoopBooleanPolyDataFilter uses an alternative algorithm to do the boolean operations.

This example can be run in three ways:

  1. BooleanOperationPolyDataFilter :- Computes the intersection of two spheres
  2. BooleanOperationPolyDataFilter -o intersection|difference|union :- Computes the intersection(difference or union) of two spheres
  3. BooleanOperationPolyDataFilter input1.vtk input2.vtk -o intersection|difference|union** :- Computes the intersection(difference or union) of two vtkPolyData's

Note

If -l is specified, the LoopBooleanPolyDataFilter is used instead of the BooleanOperationPolyDataFilter.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

BooleanPolyDataFilters.py

#!/usr/bin/env python3

from pathlib import Path

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkFiltersCore import (
    vtkCleanPolyData,
    vtkTriangleFilter
)
from vtkmodules.vtkFiltersGeneral import (
    vtkBooleanOperationPolyDataFilter,
    vtkLoopBooleanPolyDataFilter
)
from vtkmodules.vtkFiltersSources import vtkSphereSource
from vtkmodules.vtkIOGeometry import (
    vtkBYUReader,
    vtkOBJReader,
    vtkSTLReader
)
from vtkmodules.vtkIOLegacy import vtkPolyDataReader
from vtkmodules.vtkIOPLY import vtkPLYReader
from vtkmodules.vtkIOXML import vtkXMLPolyDataReader
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkPolyDataMapper,
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer
)


def get_program_parameters():
    import argparse
    description = 'How to align two vtkPolyData\'s.'
    epilogue = '''
    Try these parameters:
        ../../../src/Testing/Data/Torso.vtp ../../../src/Testing/Data/ObliqueCone.vtp -o difference
        ${DATA}/Torso.vtp difference ${DATA}/ObliqueCone.vtp
    '''
    parser = argparse.ArgumentParser(description=description, epilog=epilogue,
                                     formatter_class=argparse.RawTextHelpFormatter)
    parser.add_argument('fn1', nargs='?', default=None,
                        help='The polydata source file name,e.g. Torso.vtp.')
    parser.add_argument('fn2', nargs='?', default=None,
                        help='The polydata target file name, e.g. ObliqueCone.vtp.')
    parser.add_argument('-o', '--operation', default='intersection',
                        help='The type of operation: union, intersection, or difference.')
    parser.add_argument('-l', '--loop', action='store_false',
                        help='Use vtkLoopBooleanPolyDataFilter instead of vtkBooleanOperationPolyDataFilter.')

    args = parser.parse_args()

    return args.fn1, args.fn2, args.operation, args.loop


def main():
    colors = vtkNamedColors()

    fn1, fn2, operation, bool_pd_filter = get_program_parameters()
    if fn1 and fn2:
        # Check that the files exist.
        src_fp = Path(fn1)
        tgt_fp = Path(fn2)
        if not src_fp.is_file():
            print(f'Nonexistent source: {src_fp}')
        if not tgt_fp.is_file():
            print(f'Nonexistent target: {tgt_fp}')
        if not src_fp.is_file() or not tgt_fp.is_file():
            return

        poly1 = read_poly_data(fn1)
        tri1 = vtkTriangleFilter()
        clean1 = vtkCleanPolyData()
        input1 = (poly1 >> tri1 >> clean1).update().output

        poly2 = read_poly_data(fn2)
        tri2 = vtkTriangleFilter()
        clean2 = vtkCleanPolyData()
        input2 = (poly2 >> tri2 >> clean2).update().output

    else:
        sphere_source1 = vtkSphereSource(center=(0.25, 0, 0), phi_resolution=21, theta_resolution=21)
        sphere_source1.Update()
        input1 = sphere_source1.GetOutput()

        sphere_source2 = vtkSphereSource()
        sphere_source2.Update()
        input2 = sphere_source2.GetOutput()

    input1_mapper = vtkPolyDataMapper(scalar_visibility=False)
    input1 >> input1_mapper
    input1_actor = vtkActor(mapper=input1_mapper)
    input1_actor.property.diffuse_color = colors.GetColor3d('Tomato')
    input1_actor.property.specular = 0.6
    input1_actor.property.specular_power = 20
    bounds = input1.bounds
    input1_actor.SetPosition(bounds[1] - bounds[0], 0, 0)

    input2_mapper = vtkPolyDataMapper(scalar_visibility=False)
    input2 >> input2_mapper
    input2_actor = vtkActor(mapper=input2_mapper)
    input2_actor.property.diffuse_color = colors.GetColor3d('Mint')
    input2_actor.property.specular = 0.6
    input2_actor.property.specular_power = 20
    input2_actor.SetPosition(bounds[0] - bounds[1], 0, 0)

    if bool_pd_filter:
        boolean_operation = vtkBooleanOperationPolyDataFilter()
        if operation.lower() == 'union':
            boolean_operation.operation = vtkBooleanOperationPolyDataFilter.VTK_UNION
        elif operation.lower() == 'intersection':
            boolean_operation.operation = vtkBooleanOperationPolyDataFilter.VTK_INTERSECTION
        elif operation.lower() == 'difference':
            boolean_operation.operation = vtkBooleanOperationPolyDataFilter.VTK_DIFFERENCE
        else:
            print('Unknown operation:', operation)
            return
    else:
        boolean_operation = vtkLoopBooleanPolyDataFilter()
        if operation.lower() == 'union':
            boolean_operation.operation = vtkLoopBooleanPolyDataFilter.VTK_UNION
        elif operation.lower() == 'intersection':
            boolean_operation.operation = vtkLoopBooleanPolyDataFilter.VTK_INTERSECTION
        elif operation.lower() == 'difference':
            boolean_operation.operation = vtkLoopBooleanPolyDataFilter.VTK_DIFFERENCE
        else:
            print('Unknown operation:', operation)
            return

    boolean_operation.input_data = (0, input1)
    boolean_operation.input_data = (1, input2)

    boolean_operation_mapper = vtkPolyDataMapper(scalar_visibility=False)
    boolean_operation_actor = vtkActor(mapper=boolean_operation_mapper)
    boolean_operation >> boolean_operation_mapper
    boolean_operation_actor.property.diffuse_color = colors.GetColor3d('Banana')
    boolean_operation_actor.property.specular = 0.6
    boolean_operation_actor.property.specular_power = 20

    renderer = vtkRenderer(background=colors.GetColor3d('Silver'))
    render_window = vtkRenderWindow(size=(640, 480), window_name='BooleanPolyDataFilters')
    render_window.AddRenderer(renderer)
    ren_win_interactor = vtkRenderWindowInteractor()
    ren_win_interactor.render_window = render_window

    renderer.AddViewProp(input1_actor)
    renderer.AddViewProp(input2_actor)
    renderer.AddViewProp(boolean_operation_actor)

    viewUp = (0.0, 0.0, 1.0)
    position = (0.0, -1.0, 0.0)
    PositionCamera(renderer, viewUp, position)
    renderer.active_camera.Dolly(1.4)
    renderer.ResetCameraClippingRange()

    ren_win_interactor = vtkRenderWindowInteractor()
    ren_win_interactor.render_window = render_window

    render_window.Render()
    ren_win_interactor.Start()


def read_poly_data(file_name):
    if not file_name:
        print(f'No file name.')
        return None

    valid_suffixes = ['.g', '.obj', '.stl', '.ply', '.vtk', '.vtp']
    path = Path(file_name)
    ext = None
    if path.suffix:
        ext = path.suffix.lower()
    if path.suffix not in valid_suffixes:
        print(f'No reader for this file suffix: {ext}')
        return None

    reader = None
    if ext == '.ply':
        reader = vtkPLYReader(file_name=file_name)
    elif ext == '.vtp':
        reader = vtkXMLPolyDataReader(file_name=file_name)
    elif ext == '.obj':
        reader = vtkOBJReader(file_name=file_name)
    elif ext == '.stl':
        reader = vtkSTLReader(file_name=file_name)
    elif ext == '.vtk':
        reader = vtkPolyDataReader(file_name=file_name)
    elif ext == '.g':
        reader = vtkBYUReader(file_name=file_name)

    if reader:
        reader.update()
        poly_data = reader.output
        return poly_data
    else:
        return None


def PositionCamera(renderer, viewUp, position):
    renderer.GetActiveCamera().SetViewUp(viewUp)
    renderer.GetActiveCamera().SetPosition(position)
    renderer.ResetCamera()


if __name__ == '__main__':
    main()