py - tutorials

py_tutorials/csg_first_example.py

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+import sys
+sys.path.append("/opt/netgen/lib")
+
+from libcsg.csg import *
+from libmesh.meshing import *
+
+
+sp1 = Sphere (Point3d(1,0,0), 1)
+sp2 = Sphere (Point3d(2,0,0), 1)
+
+both = Or(sp1, sp2)
+all = And (both, OrthoBrick ( Point3d(0,0,0), Point3d (3,0.5,1)))
+
+
+geom = CSGeometry()
+geom.Add (all)
+
+
+
+param = MeshingParameters()
+param.maxh = 0.2
+mesh = GenerateMesh (geom, param)
+
+mesh.Save ("test.vol")

py_tutorials/cube.geo

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+#
+## A cube
+#
+algebraic3d
+
+# cube consisting of 6 planes:
+
+solid cube = plane (0, 0, 0; 0, 0, -1) 
+         and plane (0, 0, 0; 0, -1, 0)
+         and plane (0, 0, 0; -1, 0, 0)
+         and plane (1, 1, 1; 0, 0, 1)
+         and plane (1, 1, 1; 0, 1, 0)
+         and plane (1, 1, 1; 1, 0, 0);
+
+tlo cube;
+

py_tutorials/exportNeutral.py

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+import sys
+
+def Export (mesh, filename):
+    """ export Netgen mesh to neutral format """
+    
+    print ("export mesh in neutral format to file = ", filename)
+
+    f = open (filename, 'w')
+
+    points = mesh.Points()
+    print (len(points), file=f)
+    for p in points:
+        print (p.p[0], p.p[1], p.p[2], file=f)
+
+
+    volels = mesh.Elements3D();
+    print (len(volels), file=f)
+    for el in volels:
+        print (el.index, end="   ", file=f)
+        for j in el.vertices:
+            print (j.nr, end=" ", file=f)
+        print(file=f)
+
+
+
+

py_tutorials/mesh.py

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+from netgen.meshing import *
+from netgen.csg import *
+
+geo = CSGeometry("shaft.geo")
+
+param = MeshingParameters()
+param.maxh = 10
+print (param)
+
+m1 = GenerateMesh (geo, param)
+
+
+import exportNeutral
+exportNeutral.Export (m1, "shaft.mesh")
+
+
+

py_tutorials/shaft.geo

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+#
+## Crankshaft
+#
+algebraic3d
+solid p1 = plane (0, 0, 0; -1, 0, 0)
+         and plane (10, 0, 0; 1, 0, 0)
+         and
+         (     plane (35, 0, 28; 0, -1, 3)
+           and plane (35, 0, -28; 0, -1, -3)
+           and plane (35, 0, 0; 0, 1, 0)
+           and plane (35, -30, 0; 0, -1, 0)
+           or cylinder (-10, 0, 0; 20, 0, 0; 30)
+           or cylinder (-10, -30, 0; 20, -30, 0; 20)
+         );
+solid p2 = plane (35, 0, 0; -1, 0, 0)
+         and plane (45, 0, 0; 1, 0, 0)
+         and
+         (     plane (35, 0, 28; 0, -1, 3)
+           and plane (35, 0, -28; 0, -1, -3)
+           and plane (35, 0, 0; 0, 1, 0)
+           and plane (35, -30, 0; 0, -1, 0)
+           or cylinder (30, 0, 0; 50, 0, 0; 30)
+           or cylinder (30, -30, 0; 50, -30, 0; 20)
+         );
+solid p3 = plane (80, 0, 0; -1, 0, 0)
+         and plane (90, 0, 0; 1, 0, 0)
+         and
+         (     plane (0, 0, 28; 0, 1, 3)
+           and plane (0, 0, -28; 0, 1, -3)
+           and plane (0, 0, 0; 0, -1, 0)
+           and plane (0, 30, 0; 0, 1, 0)
+           or cylinder (70, 0, 0; 100, 0, 0; 30)
+           or cylinder (70, 30, 0; 100, 30, 0; 20)
+         );
+solid p4 = plane (115, 0, 0; -1, 0, 0)
+         and plane (125, 0, 0; 1, 0, 0)
+         and
+         (     plane (35, 0, 28; 0, 1, 3)
+           and plane (35, 0, -28; 0, 1, -3)
+           and plane (35, 0, 0; 0, -1, 0)
+           and plane (35, 30, 0; 0, 1, 0)
+           or cylinder (110, 0, 0; 130, 0, 0; 30)
+           or cylinder (110, 30, 0;130, 30, 0; 20)
+         );
+solid sh1 =   cylinder (-50, 0, 0; 10, 0, 0; 15)
+            and plane (-40, 0, 0; -1, 0, 0)
+            and plane (5, 0, 0; 1, 0, 0);
+solid sh2 =   cylinder (30, 0, 0; 90, 0, 0; 15)
+            and plane (40, 0, 0; -1, 0, 0)
+            and plane (85, 0, 0; 1, 0, 0);
+solid sh3 =   cylinder (110, 0, 0; 170, 0, 0; 15)
+            and plane (120, 0, 0; -1, 0, 0)
+            and plane (165, 0, 0; 1, 0, 0);
+
+solid pl1 = cylinder (0, -30, 0; 50, -30, 0; 10)
+            and plane (5, 0, 0; -1, 0, 0)
+            and plane (40, 0, 0; 1, 0, 0);
+solid pl2 = cylinder (80, 30, 0; 130, 30, 0; 10)
+            and plane (85, 0, 0; -1, 0, 0)
+            and plane (120, 0, 0; 1, 0, 0);
+#
+#
+solid main = p1 or p2 or p3 or p4 or sh1 or sh2 or sh3 or pl1 or pl2;
+
+tlo main;