def getTriangleMesh(fileName=None):
gmsh.model.mesh.generate(2)
if not fileName is None:
gmsh.write(fileName + ".msh")
# Renumber triangle nodeTags array with indices into aVertex
nodeTags, coord, parametricCoord = gmsh.model.mesh.getNodes(2, -1, True)
aVertex = np.asarray(coord, dtype=np.float32).reshape(len(nodeTags), 3)
nodeTagToIdx = dict()
for i, t in enumerate(nodeTags):
nodeTagToIdx[t] = i
elementTypes, elementTags, nodeTags = gmsh.model.mesh.getElements(2, -1)
assert len(elementTypes) == 1 and elementTypes[0] == 2
assert len(elementTags) == 1
assert len(nodeTags) == 1 and len(nodeTags[0]) == len(elementTags[0]) * 3
nodeTags = nodeTags[0]
aTempNodeTags = np.empty(len(nodeTags), dtype=np.int32)
for i, t in enumerate(nodeTags):
aTempNodeTags[i] = nodeTagToIdx[t]
aTriangle = aTempNodeTags.reshape(len(elementTags[0]), 3)
oMesh = Mesh(0, 0)
oMesh.aVertex = aVertex
oMesh.aTriangle = aTriangle
return oMesh
