ImplicitPolyDataDistance

#!/usr/bin/env python

import numpy as np
# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkCommonCore import (
    vtkFloatArray,
    vtkPoints
)
from vtkmodules.vtkCommonDataModel import vtkPolyData
from vtkmodules.vtkFiltersCore import vtkImplicitPolyDataDistance
from vtkmodules.vtkFiltersGeneral import vtkVertexGlyphFilter
from vtkmodules.vtkFiltersSources import vtkSphereSource
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkPolyDataMapper,
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer
)


def main():
    colors = vtkNamedColors()

    sphereSource = vtkSphereSource()
    sphereSource.SetCenter(0.0, 0.0, 0.0)
    sphereSource.SetRadius(1.0)
    sphereSource.Update()

    sphereMapper = vtkPolyDataMapper()
    sphereMapper.SetInputConnection(sphereSource.GetOutputPort())
    sphereMapper.ScalarVisibilityOff()

    sphereActor = vtkActor()
    sphereActor.SetMapper(sphereMapper)
    sphereActor.GetProperty().SetOpacity(0.3)
    sphereActor.GetProperty().SetColor(1, 0, 0)

    implicitPolyDataDistance = vtkImplicitPolyDataDistance()
    implicitPolyDataDistance.SetInput(sphereSource.GetOutput())

    # Setup a grid
    points = vtkPoints()
    step = 0.1
    for x in np.arange(-2, 2, step):
        for y in np.arange(-2, 2, step):
            for z in np.arange(-2, 2, step):
                points.InsertNextPoint(x, y, z)

    # Add distances to each point
    signedDistances = vtkFloatArray()
    signedDistances.SetNumberOfComponents(1)
    signedDistances.SetName('SignedDistances')

    # Evaluate the signed distance function at all of the grid points
    for pointId in range(points.GetNumberOfPoints()):
        p = points.GetPoint(pointId)
        signedDistance = implicitPolyDataDistance.EvaluateFunction(p)
        signedDistances.InsertNextValue(signedDistance)

    polyData = vtkPolyData()
    polyData.SetPoints(points)
    polyData.GetPointData().SetScalars(signedDistances)

    vertexGlyphFilter = vtkVertexGlyphFilter()
    vertexGlyphFilter.SetInputData(polyData)
    vertexGlyphFilter.Update()

    signedDistanceMapper = vtkPolyDataMapper()
    signedDistanceMapper.SetInputConnection(vertexGlyphFilter.GetOutputPort())
    signedDistanceMapper.ScalarVisibilityOn()

    signedDistanceActor = vtkActor()
    signedDistanceActor.SetMapper(signedDistanceMapper)

    renderer = vtkRenderer()
    renderer.AddViewProp(sphereActor)
    renderer.AddViewProp(signedDistanceActor)
    renderer.SetBackground(colors.GetColor3d('SlateGray'))

    renderWindow = vtkRenderWindow()
    renderWindow.AddRenderer(renderer)
    renderWindow.SetWindowName('ImplicitPolyDataDistance')

    renWinInteractor = vtkRenderWindowInteractor()
    renWinInteractor.SetRenderWindow(renderWindow)

    renderWindow.Render()
    renWinInteractor.Start()


if __name__ == '__main__':
    main()