Add first and second to last line in NURBS surface sets

This eases the application of boundary conditions for shells

meshpy/mesh_creation_functions/nurbs_generic.py

@@ -296,48 +296,42 @@ def get_patch_vertices(return_set, num_cps_uvw, nurbs_dimension, element):
     def get_patch_lines(return_set, num_cps_uvw, nurbs_dimension, element):
         """Get the control points positioned over the lines of a patch"""
 
-        control_points_line_1 = []
-        control_points_line_2 = []
-        control_points_line_3 = []
-        control_points_line_4 = []
-
         if nurbs_dimension == 2:
-            # Fill line 1 and line 3 with their control points
-            for i in range(num_cps_uvw[0]):
-                # Line 1 has the control points on u = [0,1], v = 0
-                cpgid_l1 = num_cps_uvw[0] * 0 + i
-                control_points_line_1.append(element.nodes[cpgid_l1])
-
-                # Line 3 has the control points on u = [0,1], v = 1
-                cpgid_l3 = num_cps_uvw[0] * (num_cps_uvw[1] - 1) + i
-                control_points_line_3.append(element.nodes[cpgid_l3])
-
-            # Fill line 2 and line 4 with their control points
-            for j in range(num_cps_uvw[1]):
-                # Line 2 has the control points on u = 1, v = [0,1]
-                cpgid_l2 = num_cps_uvw[0] * j + (num_cps_uvw[0] - 1)
-                control_points_line_2.append(element.nodes[cpgid_l2])
-
-                # Line 4 has the control points on u = 0, v = [0,1]
-                cpgid_l4 = num_cps_uvw[0] * j + 0
-                control_points_line_4.append(element.nodes[cpgid_l4])
-
-            # Create geometric sets for lines
-            return_set["line_v_min"] = GeometrySetNodes(
-                mpy.geo.line, nodes=control_points_line_1
-            )
-            return_set["line_u_max"] = GeometrySetNodes(
-                mpy.geo.line, nodes=control_points_line_2
-            )
-            return_set["line_v_max"] = GeometrySetNodes(
-                mpy.geo.line, nodes=control_points_line_3
-            )
-            return_set["line_u_min"] = GeometrySetNodes(
-                mpy.geo.line, nodes=control_points_line_4
-            )
+            name_dir = ["v", "u"]
+            name_other_dir = ["min", "min_next", "max_next", "max"]
+
+            for i_dir, i_other_dir in ((0, 1), (1, 0)):
+                n_cp_dir = num_cps_uvw[i_dir]
+                n_cp_other_dir = num_cps_uvw[i_other_dir]
+                factor_dir = 1 if i_dir == 0 else n_cp_other_dir
+                factor_other_dir = n_cp_dir if i_dir == 0 else 1
+
+                for index, i_along_other_dir in enumerate(
+                    (
+                        0,
+                        1,
+                        n_cp_other_dir - 2,
+                        n_cp_other_dir - 1,
+                    )
+                ):
+                    cp_indices = []
+                    for i_along_dir in range(n_cp_dir):
+                        cp_indices.append(
+                            i_along_other_dir * factor_other_dir
+                            + i_along_dir * factor_dir
+                        )
+                    set_name = f"line_{name_dir[i_dir]}_{name_other_dir[index]}"
+                    return_set[set_name] = GeometrySetNodes(
+                        mpy.geo.line,
+                        nodes=[element.nodes[i_node] for i_node in cp_indices],
+                    )
 
         elif nurbs_dimension == 3:
             # Define the rest of the lines to define a volume
+            control_points_line_1 = []
+            control_points_line_2 = []
+            control_points_line_3 = []
+            control_points_line_4 = []
             control_points_line_5 = []
             control_points_line_6 = []
             control_points_line_7 = []

tests/reference-files/test_nurbs_couple_nurbs_meshes_reference.dat

@@ -73,38 +73,74 @@ NODE 5 DLINE 1
 NODE 10 DLINE 1
 NODE 15 DLINE 1
 NODE 20 DLINE 1
-NODE 1 DLINE 2
-NODE 6 DLINE 2
-NODE 11 DLINE 2
-NODE 16 DLINE 2
+NODE 4 DLINE 2
+NODE 9 DLINE 2
+NODE 14 DLINE 2
+NODE 19 DLINE 2
+NODE 1 DLINE 3
+NODE 6 DLINE 3
+NODE 11 DLINE 3
 NODE 16 DLINE 3
-NODE 17 DLINE 3
-NODE 18 DLINE 3
-NODE 19 DLINE 3
-NODE 20 DLINE 3
-NODE 1 DLINE 4
 NODE 2 DLINE 4
-NODE 3 DLINE 4
-NODE 4 DLINE 4
-NODE 5 DLINE 4
-NODE 1 DLINE 5
-NODE 6 DLINE 5
-NODE 11 DLINE 5
+NODE 7 DLINE 4
+NODE 12 DLINE 4
+NODE 17 DLINE 4
 NODE 16 DLINE 5
-NODE 21 DLINE 6
-NODE 25 DLINE 6
-NODE 29 DLINE 6
-NODE 33 DLINE 6
-NODE 16 DLINE 7
-NODE 33 DLINE 7
-NODE 34 DLINE 7
-NODE 35 DLINE 7
-NODE 36 DLINE 7
-NODE 1 DLINE 8
-NODE 21 DLINE 8
-NODE 22 DLINE 8
-NODE 23 DLINE 8
-NODE 24 DLINE 8
+NODE 17 DLINE 5
+NODE 18 DLINE 5
+NODE 19 DLINE 5
+NODE 20 DLINE 5
+NODE 11 DLINE 6
+NODE 12 DLINE 6
+NODE 13 DLINE 6
+NODE 14 DLINE 6
+NODE 15 DLINE 6
+NODE 1 DLINE 7
+NODE 2 DLINE 7
+NODE 3 DLINE 7
+NODE 4 DLINE 7
+NODE 5 DLINE 7
+NODE 6 DLINE 8
+NODE 7 DLINE 8
+NODE 8 DLINE 8
+NODE 9 DLINE 8
+NODE 10 DLINE 8
+NODE 1 DLINE 9
+NODE 6 DLINE 9
+NODE 11 DLINE 9
+NODE 16 DLINE 9
+NODE 24 DLINE 10
+NODE 28 DLINE 10
+NODE 32 DLINE 10
+NODE 36 DLINE 10
+NODE 21 DLINE 11
+NODE 25 DLINE 11
+NODE 29 DLINE 11
+NODE 33 DLINE 11
+NODE 22 DLINE 12
+NODE 26 DLINE 12
+NODE 30 DLINE 12
+NODE 34 DLINE 12
+NODE 16 DLINE 13
+NODE 33 DLINE 13
+NODE 34 DLINE 13
+NODE 35 DLINE 13
+NODE 36 DLINE 13
+NODE 11 DLINE 14
+NODE 29 DLINE 14
+NODE 30 DLINE 14
+NODE 31 DLINE 14
+NODE 32 DLINE 14
+NODE 1 DLINE 15
+NODE 21 DLINE 15
+NODE 22 DLINE 15
+NODE 23 DLINE 15
+NODE 24 DLINE 15
+NODE 6 DLINE 16
+NODE 25 DLINE 16
+NODE 26 DLINE 16
+NODE 27 DLINE 16
+NODE 28 DLINE 16
 -------------------------------------------------------------DSURF-NODE TOPOLOGY
 NODE 1 DSURFACE 1
 NODE 2 DSURFACE 1

tests/reference-files/test_nurbs_flat_plate_2d_reference.dat

@@ -49,21 +49,43 @@ NODE 16 DLINE 1
 NODE 20 DLINE 1
 NODE 24 DLINE 1
 NODE 28 DLINE 1
-NODE 1 DLINE 2
-NODE 5 DLINE 2
-NODE 9 DLINE 2
-NODE 13 DLINE 2
-NODE 17 DLINE 2
-NODE 21 DLINE 2
-NODE 25 DLINE 2
+NODE 3 DLINE 2
+NODE 7 DLINE 2
+NODE 11 DLINE 2
+NODE 15 DLINE 2
+NODE 19 DLINE 2
+NODE 23 DLINE 2
+NODE 27 DLINE 2
+NODE 1 DLINE 3
+NODE 5 DLINE 3
+NODE 9 DLINE 3
+NODE 13 DLINE 3
+NODE 17 DLINE 3
+NODE 21 DLINE 3
 NODE 25 DLINE 3
-NODE 26 DLINE 3
-NODE 27 DLINE 3
-NODE 28 DLINE 3
-NODE 1 DLINE 4
 NODE 2 DLINE 4
-NODE 3 DLINE 4
-NODE 4 DLINE 4
+NODE 6 DLINE 4
+NODE 10 DLINE 4
+NODE 14 DLINE 4
+NODE 18 DLINE 4
+NODE 22 DLINE 4
+NODE 26 DLINE 4
+NODE 25 DLINE 5
+NODE 26 DLINE 5
+NODE 27 DLINE 5
+NODE 28 DLINE 5
+NODE 21 DLINE 6
+NODE 22 DLINE 6
+NODE 23 DLINE 6
+NODE 24 DLINE 6
+NODE 1 DLINE 7
+NODE 2 DLINE 7
+NODE 3 DLINE 7
+NODE 4 DLINE 7
+NODE 5 DLINE 8
+NODE 6 DLINE 8
+NODE 7 DLINE 8
+NODE 8 DLINE 8
 -------------------------------------------------------------DSURF-NODE TOPOLOGY
 NODE 1 DSURFACE 1
 NODE 2 DSURFACE 1