3 \page tui_use_existing_faces Use existing faces
5 This sample demonstrates how to use <b>Use existing faces</b> algorithm,
6 which is actulally just a stub allowing to use your own 2D algoritm
14 # define my 2D algorithm
15 def my2DMeshing( geomFace ):
17 # find gravity center of geomFace
18 gcXYZ = geompy.PointCoordinates( geompy.MakeCDG( geomFace ))
20 # define order and orientation of edges
22 geomEdges = geompy.SubShapeAll( geomFace, geompy.ShapeType["EDGE"])
23 sortedEdges.append(( geomEdges.pop(0), True ))
25 prevEdge_rev = sortedEdges[ -1 ]
26 prevVV = geompy.SubShapeAll( prevEdge_rev[0], geompy.ShapeType["VERTEX"])
27 prevV2 = prevVV[ prevEdge_rev[1] ]
29 for iE in range( len( geomEdges )):
30 v1,v2 = geompy.SubShapeAll( geomEdges[ iE ], geompy.ShapeType["VERTEX"])
31 same1,same2 = [( geompy.MinDistance( prevV2, v ) < 1e-7 ) for v in [v1,v2] ]
32 if not same1 and not same2: continue
33 sortedEdges.append(( geomEdges.pop( iE ), same1 ))
39 # put nodes on edges in a right order
41 for edge, isForward in sortedEdges:
42 v1,v2 = geompy.SubShapeAll( edge, geompy.ShapeType["VERTEX"])
43 edgeNodes = mesh.GetSubMeshNodesId( v2, all=False ) + \
44 mesh.GetSubMeshNodesId( edge, all=False ) + \
45 mesh.GetSubMeshNodesId( v1, all=False )
46 if not isForward: edgeNodes.reverse()
47 nodes.extend( edgeNodes[:-1] )
49 # create nodes inside the geomFace
54 nXYZ = mesh.GetNodeXYZ( n )
55 newXYZ = np.add( np.multiply( r1, gcXYZ ), np.multiply( r2, nXYZ ))
56 nodesInside.append( mesh.AddNode( newXYZ[0], newXYZ[1], newXYZ[2] ))
57 mesh.SetNodeOnFace( nodesInside[-1], geomFace, 0, 0 )
59 # find out orientation of faces to create
61 faceNorm = geompy.GetNormal( geomFace )
62 v1,v2 = [ geompy.PointCoordinates( v ) \
63 for v in geompy.SubShapeAll( faceNorm, geompy.ShapeType["VERTEX"]) ]
64 faceNormXYZ = np.subtract( v2, v1 )
65 outDirXYZ = np.subtract( v1, [ 50, 50, 50 ] )
66 if np.dot( faceNormXYZ, outDirXYZ ) < 0: # reversed face
67 faceNormXYZ = np.multiply( -1., faceNormXYZ )
69 e1 = np.subtract( mesh.GetNodeXYZ( nodes[0] ), mesh.GetNodeXYZ( nodes[1] ))
70 e2 = np.subtract( mesh.GetNodeXYZ( nodes[0] ), mesh.GetNodeXYZ( nodesInside[0] ))
71 meshNorm = np.cross( e1, e2 )
73 reverse = ( np.dot( faceNormXYZ, meshNorm ) < 0 )
78 n1, n2, n3, n4 = nodes[iN-1], nodes[iN-2], nodesInside[iN-2], nodesInside[iN-1]
81 f = mesh.AddFace( [n1, n2, n3, n4] )
83 f = mesh.AddFace( [n4, n3, n2, n1] )
84 # new faces must be assigned to geometry to allow 3D algorithm finding them
85 mesh.SetMeshElementOnShape( f, geomFace )
89 polygon = mesh.AddPolygonalFace( nodesInside )
90 mesh.SetMeshElementOnShape( polygon, geomFace )
94 # create geometry and get faces to mesh with my2DMeshing()
95 box = geompy.MakeBoxDXDYDZ( 100, 100, 100 )
96 f1 = geompy.SubShapeAll( box, geompy.ShapeType["FACE"])[0]
97 f2 = geompy.GetOppositeFace( box, f1 )
98 geompy.addToStudy( box, "box" )
99 geompy.addToStudy( f1, "f1" )
100 geompy.addToStudy( f2, "f2" )
103 mesh = smesh.Mesh( box )
104 mesh.Segment().NumberOfSegments( 5 )
109 mesh.UseExistingFaces(f1) # UseExistingFaces() allows using my2DMeshing()
110 mesh.UseExistingFaces(f2)
113 assert mesh.Compute()
117 assert mesh.Compute()
122 \image html use_existing_face_sample_mesh.png