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DiscreteFlyingEdges3D

web-test/PythonicAPI/Modelling/DiscreteFlyingEdges3D

Description

Creates surfaces from labeled data. Volume data does not always contain samples of continuous data. A volume may contain discrete integer values, often the result of segmentation.

vtkDiscreteFlyingEdges3D or vtkDiscreteMarchingCubes create surfaces from these segmented volumes using a modified flying edges or marching cubes algorithm.

The algorithm generates one or more models representing the boundaries between the specified label and the adjacent structures. One or more label values must be specified to generate the models. The boundary positions are always defined to be half-way between adjacent voxels.

An option is provided to use vtkDiscreteMarchingCubes instead of vtkDiscreteFlyingEdges3D.

Seealso

SmoothDiscreteFlyingEdges3D produces smooth models.

Question

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

Code

DiscreteFlyingEdges3D.py

#!/usr/bin/env python3

from dataclasses import dataclass

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkCommonCore import (
    vtkLookupTable,
    vtkMinimalStandardRandomSequence
)
from vtkmodules.vtkCommonDataModel import (
    vtkImageData,
    vtkSphere
)
from vtkmodules.vtkFiltersGeneral import (
    vtkDiscreteFlyingEdges3D,
    vtkDiscreteMarchingCubes
)
from vtkmodules.vtkImagingCore import vtkImageThreshold
from vtkmodules.vtkImagingHybrid import vtkSampleFunction
from vtkmodules.vtkImagingMath import vtkImageMathematics
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkPolyDataMapper,
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer
)


def get_program_parameters():
    import argparse
    description = 'Create surfaces from labeled data.'
    epilogue = '''
    '''
    parser = argparse.ArgumentParser(description=description, epilog=epilogue,
                                     formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument('-m', '--marching_cubes', action='store_false',
                        help='Use Marching Cubes instead of Flying Edges.')
    args = parser.parse_args()
    return args.marching_cubes


def main():
    use_flying_edges = get_program_parameters()

    colors = vtkNamedColors()

    # Create the RenderWindow, Renderer, Interactor
    ren = vtkRenderer(background=colors.GetColor3d('Burlywood'))
    ren_win = vtkRenderWindow(window_name='DiscreteMarchingCubes')
    ren_win.AddRenderer(ren)
    iren = vtkRenderWindowInteractor()
    iren.SetRenderWindow(ren_win)

    n = 20
    radius = 8
    blob = make_blob(n, radius)

    if use_flying_edges:
        try:
            discrete = vtkDiscreteFlyingEdges3D()
        except AttributeError:
            discrete = vtkDiscreteMarchingCubes()
    else:
        discrete = vtkDiscreteMarchingCubes()
    discrete.GenerateValues(n, 1, n)

    lut = make_colors(n)

    mapper = vtkPolyDataMapper(lookup_table=lut, scalar_range=(0, lut.number_of_colors))
    blob >> discrete >> mapper
    actor = vtkActor(mapper=mapper)

    ren.AddActor(actor)

    ren_win.Render()

    iren.Start()


def make_blob(n, radius):
    blob_image = vtkImageData()

    max_r = 50 - 2.0 * radius
    random_sequence = vtkMinimalStandardRandomSequence(seed=5071)
    for i in range(0, n):

        x = random_sequence.GetRangeValue(-max_r, max_r)
        random_sequence.Next()
        y = random_sequence.GetRangeValue(-max_r, max_r)
        random_sequence.Next()
        z = random_sequence.GetRangeValue(-max_r, max_r)
        random_sequence.Next()

        sphere = vtkSphere(radius=radius, center=(int(x), int(y), int(z)))

        sampler = vtkSampleFunction(implicit_function=sphere, output_scalar_type=ImageCast.OutputScalarType.VTK_FLOAT,
                                    sample_dimensions=(100, 100, 100), model_bounds=(-50, 50, -50, 50, -50, 50))

        thres = vtkImageThreshold(replace_in=True, replace_out=True, in_value=i + 1, out_value=0)
        thres.ThresholdByLower(radius * radius)
        (sampler >> thres).update()
        if i == 0:
            blob_image.DeepCopy(thres.output)

        max_value = vtkImageMathematics(operation=ImageMathematics.Operation.VTK_MAX)
        ((blob_image, thres) >> max_value).update()

        blob_image.DeepCopy(max_value.output)

    return blob_image


def make_colors(n):
    """
    Generate some random colors
    :param n: The number of colors.
    :return: The lookup table.
    """

    lut = vtkLookupTable(number_of_colors=n, table_range=(0, n - 1), scale=LookupTable.Scale.VTK_SCALE_LINEAR)
    lut.Build()
    lut.table_value = (0, 0.0, 0.0, 0.0, 1.0)

    random_sequence = vtkMinimalStandardRandomSequence()
    random_sequence.SetSeed(5071)
    for i in range(1, n):
        r = random_sequence.GetRangeValue(0.4, 1)
        random_sequence.Next()
        g = random_sequence.GetRangeValue(0.4, 1)
        random_sequence.Next()
        b = random_sequence.GetRangeValue(0.4, 1)
        random_sequence.Next()
        lut.table_value = (i, r, g, b, 1.0)

    return lut


@dataclass(frozen=True)
class ImageCast:
    @dataclass(frozen=True)
    class OutputScalarType:
        VTK_CHAR: int = 2
        VTK_UNSIGNED_CHAR: int = 3
        VTK_SHORT: int = 4
        VTK_UNSIGNED_SHORT: int = 5
        VTK_INT: int = 6
        VTK_UNSIGNED_INT: int = 7
        VTK_LONG: int = 8
        VTK_UNSIGNED_LONG: int = 9
        VTK_FLOAT: int = 10
        VTK_DOUBLE: int = 11


@dataclass(frozen=True)
class ImageMathematics:
    @dataclass(frozen=True)
    class Operation:
        VTK_ADD: int = 0
        VTK_SUBTRACT: int = 1
        VTK_MULTIPLY: int = 2
        VTK_DIVIDE: int = 3
        VTK_INVERT: int = 4
        VTK_SIN: int = 5
        VTK_COS: int = 6
        VTK_EXP: int = 7
        VTK_LOG: int = 8
        VTK_ABS: int = 9
        VTK_SQR: int = 10
        VTK_SQRT: int = 11
        VTK_MIN: int = 12
        VTK_MAX: int = 13
        VTK_ATAN: int = 14
        VTK_ATAN2: int = 15
        VTK_MULTIPLYBYK: int = 16
        VTK_ADDC: int = 17
        VTK_CONJUGATE: int = 18
        VTK_COMPLEX_MULTIPLY: int = 19
        VTK_REPLACECBYK: int = 20


@dataclass(frozen=True)
class LookupTable:
    @dataclass(frozen=True)
    class Scale:
        VTK_SCALE_LINEAR: int = 0
        VTK_SCALE_LOG10: int = 1


if __name__ == '__main__':
    main()