which is actulally just a stub allowing to use your own 2D algoritm
implemented in Python.
-
-\code
-import smesh, geompy
-import numpy as np
-
-# define my 2D algorithm
-def my2DMeshing( geomFace ):
-
- # find gravity center of geomFace
- gcXYZ = geompy.PointCoordinates( geompy.MakeCDG( geomFace ))
-
- # define order and orientation of edges
- sortedEdges = []
- geomEdges = geompy.SubShapeAll( geomFace, geompy.ShapeType["EDGE"])
- sortedEdges.append(( geomEdges.pop(0), True ))
- while geomEdges:
- prevEdge_rev = sortedEdges[ -1 ]
- prevVV = geompy.SubShapeAll( prevEdge_rev[0], geompy.ShapeType["VERTEX"])
- prevV2 = prevVV[ prevEdge_rev[1] ]
- found = False
- for iE in range( len( geomEdges )):
- v1,v2 = geompy.SubShapeAll( geomEdges[ iE ], geompy.ShapeType["VERTEX"])
- same1,same2 = [( geompy.MinDistance( prevV2, v ) < 1e-7 ) for v in [v1,v2] ]
- if not same1 and not same2: continue
- sortedEdges.append(( geomEdges.pop( iE ), same1 ))
- found = True
- break
- assert found
- sortedEdges.reverse()
-
- # put nodes on edges in a right order
- nodes = []
- for edge, isForward in sortedEdges:
- v1,v2 = geompy.SubShapeAll( edge, geompy.ShapeType["VERTEX"])
- edgeNodes = mesh.GetSubMeshNodesId( v2, all=False ) + \
- mesh.GetSubMeshNodesId( edge, all=False ) + \
- mesh.GetSubMeshNodesId( v1, all=False )
- if not isForward: edgeNodes.reverse()
- nodes.extend( edgeNodes[:-1] )
-
- # create nodes inside the geomFace
- r1 = 0.6
- r2 = 1 - r1
- nodesInside = []
- for n in nodes:
- nXYZ = mesh.GetNodeXYZ( n )
- newXYZ = np.add( np.multiply( r1, gcXYZ ), np.multiply( r2, nXYZ ))
- nodesInside.append( mesh.AddNode( newXYZ[0], newXYZ[1], newXYZ[2] ))
- mesh.SetNodeOnFace( nodesInside[-1], geomFace, 0, 0 )
-
- # find out orientation of faces to create
- # geomFace normal
- faceNorm = geompy.GetNormal( geomFace )
- v1,v2 = [ geompy.PointCoordinates( v ) \
- for v in geompy.SubShapeAll( faceNorm, geompy.ShapeType["VERTEX"]) ]
- faceNormXYZ = np.subtract( v2, v1 )
- outDirXYZ = np.subtract( v1, [ 50, 50, 50 ] )
- if np.dot( faceNormXYZ, outDirXYZ ) < 0: # reversed face
- faceNormXYZ = np.multiply( -1., faceNormXYZ )
- # mesh face normal
- e1 = np.subtract( mesh.GetNodeXYZ( nodes[0] ), mesh.GetNodeXYZ( nodes[1] ))
- e2 = np.subtract( mesh.GetNodeXYZ( nodes[0] ), mesh.GetNodeXYZ( nodesInside[0] ))
- meshNorm = np.cross( e1, e2 )
- # faces orientation
- reverse = ( np.dot( faceNormXYZ, meshNorm ) < 0 )
-
- # create mesh faces
- iN = len( nodes )
- while iN:
- n1, n2, n3, n4 = nodes[iN-1], nodes[iN-2], nodesInside[iN-2], nodesInside[iN-1]
- iN -= 1
- if reverse:
- f = mesh.AddFace( [n1, n2, n3, n4] )
- else:
- f = mesh.AddFace( [n4, n3, n2, n1] )
- # new faces must be assigned to geometry to allow 3D algorithm finding them
- mesh.SetMeshElementOnShape( f, geomFace )
-
- if reverse:
- nodesInside.reverse()
- polygon = mesh.AddPolygonalFace( nodesInside )
- mesh.SetMeshElementOnShape( polygon, geomFace )
-
- return
-
-# create geometry and get faces to mesh with my2DMeshing()
-box = geompy.MakeBoxDXDYDZ( 100, 100, 100 )
-f1 = geompy.SubShapeAll( box, geompy.ShapeType["FACE"])[0]
-f2 = geompy.GetOppositeFace( box, f1 )
-geompy.addToStudy( box, "box" )
-geompy.addToStudy( f1, "f1" )
-geompy.addToStudy( f2, "f2" )
-
-# compute 1D mesh
-mesh = smesh.Mesh( box )
-mesh.Segment().NumberOfSegments( 5 )
-mesh.Compute()
-
-# compute 2D mesh
-mesh.Quadrangle()
-mesh.UseExistingFaces(f1) # UseExistingFaces() allows using my2DMeshing()
-mesh.UseExistingFaces(f2)
-my2DMeshing( f1 )
-my2DMeshing( f2 )
-assert mesh.Compute()
-
-# compute 3D mesh
-mesh.Prism()
-assert mesh.Compute()
-
-\endcode
+\include use_existing_faces.py
+<a href="../../examples/SMESH/use_existing_faces.py">Download this script</a>
Resulting mesh:
\image html use_existing_face_sample_mesh.png
