Reimplement edge based mesh import

We don't use foreach_set, since for some reason doing it with foreach_set requires edit mode to be toggled for the edges to be visible. We make the assumption that an object is either edge based or face based, but not both.

src/ifcblenderexport/blenderbim/bim/import_ifc.py

@@ -1671,23 +1671,30 @@ class IfcImporter():
 
             mesh = bpy.data.meshes.new(geometry.id)
 
-            vertices = geometry.verts
-            num_vertices = len(vertices) // 3
-            vertex_index = geometry.faces
-            total_faces = len(geometry.faces)
-            loop_start = range(0, total_faces, 3)
-            num_loops = total_faces // 3
-            loop_total = [3] * num_loops
-            num_vertex_indices = len(vertex_index)
+            if geometry.faces:
+                num_vertices = len(geometry.verts) // 3
+                total_faces = len(geometry.faces)
+                loop_start = range(0, total_faces, 3)
+                num_loops = total_faces // 3
+                loop_total = [3] * num_loops
+                num_vertex_indices = len(geometry.faces)
 
-            mesh.vertices.add(num_vertices)
-            mesh.vertices.foreach_set('co', vertices)
-            mesh.loops.add(num_vertex_indices)
-            mesh.loops.foreach_set('vertex_index', vertex_index)
-            mesh.polygons.add(num_loops)
-            mesh.polygons.foreach_set('loop_start', loop_start)
-            mesh.polygons.foreach_set('loop_total', loop_total)
-            mesh.update()
+                mesh.vertices.add(num_vertices)
+                mesh.vertices.foreach_set('co', geometry.verts)
+                mesh.loops.add(num_vertex_indices)
+                mesh.loops.foreach_set('vertex_index', geometry.faces)
+                mesh.polygons.add(num_loops)
+                mesh.polygons.foreach_set('loop_start', loop_start)
+                mesh.polygons.foreach_set('loop_total', loop_total)
+                mesh.update()
+            else:
+                e = geometry.edges
+                v = geometry.verts
+                vertices = [[v[i], v[i + 1], v[i + 2]]
+                         for i in range(0, len(v), 3)]
+                edges = [[e[i], e[i + 1]]
+                         for i in range(0, len(e), 2)]
+                mesh.from_pydata(vertices, edges, [])
 
             ios_materials = []
             for mat in geometry.materials:

src/ifcblenderexport/blenderbim/bim/prop.py

@@ -1082,7 +1082,7 @@ class RepresentationItem(PropertyGroup):
 
 class BIMMeshProperties(PropertyGroup):
     is_wireframe: BoolProperty(name="Is Wireframe")
-    is_native: BoolProperty(name="Is Native")
+    is_native: BoolProperty(name="Is Native", default=False)
     is_swept_solid: BoolProperty(name="Is Swept Solid")
     swept_solids: CollectionProperty(name="Swept Solids", type=SweptSolid)
     is_parametric: BoolProperty(name='Is Parametric', default=False)

src/ifcblenderexport/blenderbim/bim/ui.py

@@ -846,7 +846,8 @@ class BIM_PT_bim(Panel):
             row = layout.row()
             row.prop(bim_properties, "ifc_userdefined_type")
         row = layout.row()
-        row.operator("bim.assign_class")
+        op = row.operator("bim.assign_class")
+        op.object_name = ''
 
         row = layout.row(align=True)
         row.operator("bim.select_class")