meshing/lods/lods.py

Refer to the Level of Details (LOD's) 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:
 
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# 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
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# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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# POSSIBILITY OF SUCH DAMAGE.
 
 
import sys
from pathlib import Path
import os
 
import cadexchanger.CadExCore as cadex
 
sys.path.append(os.path.abspath(os.path.dirname(Path(__file__).resolve()) + r"/../../"))
import cadex_license as license
 
def NumberOfTriangles(thePoly: cadex.ModelData_PolyRepresentation) -> int:
    trianglesNB = 0
 
    aList = thePoly.Get()
    for aPVS in aList:
        if aPVS.TypeId() == cadex.ModelData_IndexedTriangleSet.GetTypeId():
            anITS = cadex.ModelData_IndexedTriangleSet.Cast(aPVS)
            trianglesNB += anITS.NumberOfFaces()
    return trianglesNB
 
def CreateSphereBRep(thePosition: cadex.ModelData_Point, theRadius: float) -> cadex.ModelData_BRepRepresentation:
    aSphere = cadex.ModelAlgo_TopoPrimitives.CreateSphere(thePosition, theRadius)
    aBody = cadex.ModelData_Body.Create(aSphere)
    aBRep = cadex.ModelData_BRepRepresentation(aBody)
    return aBRep
 
def AddPolyToPart(thePart: cadex.ModelData_Part, theLOD):
    aBRep = thePart.BRepRepresentation()
    aParam = cadex.ModelAlgo_BRepMesherParameters(theLOD)
    aMesher = cadex.ModelAlgo_BRepMesher(aParam)
 
    aPoly = aMesher.Compute(aBRep)
 
    thePart.AddRepresentation(aPoly)
    print(f"A polygonal representation with {NumberOfTriangles(aPoly)} triangles has been added");
 
 
def main():
    aKey = license.Value()
 
    if not cadex.LicenseManager.Activate(aKey):
        print("Failed to activate CAD Exchanger license.")
        return 1
 
    aBRep = CreateSphereBRep(cadex.ModelData_Point(0.0, 0.0, 0.0), 10)
    aPart = cadex.ModelData_Part(aBRep, cadex.Base_UTF16String("Sphere"))
 
    AddPolyToPart(aPart, cadex.ModelAlgo_BRepMesherParameters.Coarse)
    AddPolyToPart(aPart, cadex.ModelAlgo_BRepMesherParameters.Medium)
    AddPolyToPart(aPart, cadex.ModelAlgo_BRepMesherParameters.Fine)
 
    aModel = cadex.ModelData_Model()
    aModel.AddRoot(aPart)
 
    if not cadex.ModelData_ModelWriter().Write(aModel, cadex.Base_UTF16String("out/SphereWithLODs.cdx")):
        print("Unable to save the model")
        return 1
 
    print("Completed")
    return 0
 
if __name__ == "__main__":
    sys.exit(main())