meshing/visualizationmesher/visualizationmesher.py

Refer to the Visualization Mesher Example.

#!/usr/bin/env python3
 
# $Id$
 
# Copyright (C) 2008-2014, Roman Lygin. All rights reserved.
# Copyright (C) 2014-2023, CADEX. All rights reserved.
 
# This file is part of the CAD Exchanger software.
 
# You may use this file under the terms of the BSD license as follows:
 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
 
 
import sys
from pathlib import Path
import os
 
import cadexchanger.CadExCore as cadex
import cadexchanger.CadExMesh as mesh
 
sys.path.append(os.path.abspath(os.path.dirname(Path(__file__).resolve()) + r"/../../"))
import cadex_license as license
 
import math
 
 
class FirstFaceGetter(cadex.ModelData_Model_VoidElementVisitor):
    def __init__(self):
        cadex.ModelData_Model_VoidElementVisitor.__init__(self)
        self.myFace = None
 
    def VisitPart(self, thePart: cadex.ModelData_Part):
        if self.myFace is None:
            aBRep = thePart.BRepRepresentation()
            self.ExploreBRep(aBRep)
 
    def ExploreBRep(self, theBRep: cadex.ModelData_BRepRepresentation):
        aBodyList = theBRep.Get()
        aFirstBody = aBodyList.First()
        for aShape in cadex.ModelData_Shape_Iterator(aFirstBody, cadex.ModelData_ST_Face):
            self.myFace = cadex.ModelData_Face.Cast(aShape)
            break
            
    def FirstFace(self):
        return self.myFace
 
def PrintFaceToPolyAssociation(theFace: cadex.ModelData_Face,
                               theAssociations: cadex.ModelData_BRepToPolyAssociations):
    aMeshPatch = theAssociations.Get(theFace)
    anITS = cadex.ModelData_IndexedTriangleSet.Cast(aMeshPatch.PVS())
    aTriangleIndices = aMeshPatch.Indices()
 
    print(f"Face triangulation contains {len(aTriangleIndices)} triangles.")
 
    aNumberOfTrianglesToPrint = min(4, len(aTriangleIndices))
 
    for i in range(aNumberOfTrianglesToPrint):
        aTriangleIndex = aTriangleIndices.Element(i)
        print(f"Triangle index {aTriangleIndex} with vertices: ")
        for aVertexNumber in range(3):
            aVertexIndex = anITS.CoordinateIndex(aTriangleIndex, aVertexNumber);
            aPoint = anITS.Coordinate(aVertexIndex);
            print(f"  Vertex index {aVertexIndex} with coords",
                  f"(X: {aPoint.X()}, Y: {aPoint.Y()}, Z: {aPoint.Z()})")
 
def main(theSource: str):
    aKey = license.Value()
 
    if not cadex.LicenseManager.Activate(aKey):
        print("Failed to activate CAD Exchanger license.")
        return 1
 
    aModel = cadex.ModelData_Model()
 
    if not cadex.ModelData_ModelReader().Read(cadex.Base_UTF16String(theSource), aModel):
        print("Failed to read the file " + theSource)
        return 1
 
    # Set up mesher and parameters
    aParam = cadex.ModelAlgo_BRepMesherParameters()
    aParam.SetAngularDeflection(math.pi * 10 / 180)
    aParam.SetChordalDeflection(0.003)
    aParam.SetSaveBRepToPolyAssociations(True)
 
    aMesher = cadex.ModelAlgo_BRepMesher(aParam)
    aMesher.Compute(aModel, True)
    
    # Example of using B-Rep to Poly representation associations:
    aVisitor = FirstFaceGetter();
    aModel.AcceptElementVisitor(aVisitor);
 
    aFace = aVisitor.FirstFace();
    aBRepToPolyAssociations = aMesher.BRepToPolyAssociations();
    PrintFaceToPolyAssociation(aFace, aBRepToPolyAssociations)
    
    # Save the result
    if not cadex.ModelData_ModelWriter().Write(aModel, cadex.Base_UTF16String("out/VisMesher.cdx")):
        print("Unable to save the model")
        return 1
 
    print("Completed")
    return 0
 
if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: " + os.path.abspath(Path(__file__).resolve()) + " <input_file>, where:")
        print("    <input_file>  is a name of the XML file to be read")
        sys.exit(1)
 
    aSource = os.path.abspath(sys.argv[1])
 
    sys.exit(main(aSource))