Manually_triangulate_mesh.py

import vtk

def checkQualityAndTriangulate():
    reader = vtk.vtkSTLReader()
    reader.SetFileName('data/3D_data/demoparts/test.stl')
    reader.Update()
    srcPolyData = reader.GetOutput()

    triangleFilter = vtk.vtkTriangleFilter()
    triangleFilter.SetInputConnection(reader.GetOutputPort())
    triangleFilter.Update()

    mesh = triangleFilter.GetOutput()
    qualityFilter = vtk.vtkMeshQuality()
    qualityFilter.SetInputData(mesh)
    qualityFilter.SetTriangleQualityMeasureToArea()
    qualityFilter.Update()

    featureEdges = vtk.vtkFeatureEdges()
    featureEdges.SetInputData(srcPolyData)
    featureEdges.SetBoundaryEdges(1)
    featureEdges.SetFeatureEdges(0)
    featureEdges.SetNonManifoldEdges(0)
    featureEdges.SetManifoldEdges(0)

    featureEdges.Update()

    numberOfOpenEdges = featureEdges.GetOutput().GetNumberOfLines()

    print("open edges, there are: ", numberOfOpenEdges)
    print("================== START FILLING HOLES ====================")
    #clean up the mesh
    boundaryClean = vtk.vtkCleanPolyData()
    boundaryClean.SetInputData(srcPolyData)
    boundaryClean.Update()

    region = vtk.vtkPolyDataConnectivityFilter()
    meshAppend = vtk.vtkAppendPolyData()
    boundaryStrips = vtk.vtkStripper()
    boundaryPoly = vtk.vtkPolyData()
    boundaryTri = vtk.vtkTriangleFilter()

    meshAppend.AddInputData(boundaryClean.GetOutput())
    meshAppend.AddInputData(boundaryTri.GetOutput())

    region.SetInputData(featureEdges.GetOutput())
    region.SetExtractionMode(6)

    boundaryStrips.SetInputData(region.GetOutput())
    boundaryTri.SetInputData(boundaryPoly)

    boundaryClean.SetInputData(meshAppend.GetOutput())
    boundaryClean.SetTolerance(0.0)
    boundaryClean.SetConvertLinesToPoints(0)
    boundaryClean.SetConvertPolysToLines(0)
    boundaryClean.SetConvertStripsToPolys(0)

    featureEdges.SetInputData(boundaryClean.GetOutput())
    i = 0
    while numberOfOpenEdges != 0:
        print('number of open edges: ', numberOfOpenEdges)
        region.Update()
        #create polygonal patches
        boundaryStrips.Update()

        boundaryPoly.Initialize()
        boundaryPoly.SetPoints(boundaryStrips.GetOutput().GetPoints())
        boundaryPoly.SetPolys(boundaryStrips.GetOutput().GetLines())
        boundaryPoly.Modified()
        # triangulate the polygonal patch
        boundaryTri.Update()
        meshAppend.Update()
        # remove dup
        boundaryClean.Update()

        featureEdges.Update()

        numberOfOpenEdges = featureEdges.GetOutput().GetNumberOfLines()

    print('........................ done ')


    out = vtk.vtkPolyData()
    out.DeepCopy(boundaryClean.GetOutput())
    writerFinal = vtk.vtkSTLWriter()
    writerFinal.SetFileTypeToBinary()
    writerFinal.SetInputData(out)
    writerFinal.SetFileName('data/3D_data/demoparts/improve_final.stl')
    writerFinal.Update()
    writerFinal.Write()


if __name__ == '__main__':
    checkQualityAndTriangulate()