// loop through submesh border edges on basemesh, map to submesh, and
// pin those edges / vertices
public static void FixSubmeshBoundaryEdges(MeshConstraints cons, DSubmesh3 sub)
{
Debug.Assert(sub.BaseBorderE != null);
foreach (int base_eid in sub.BaseBorderE)
{
Index2i base_ev = sub.BaseMesh.GetEdgeV(base_eid);
Index2i sub_ev = sub.MapVerticesToSubmesh(base_ev);
int sub_eid = sub.SubMesh.FindEdge(sub_ev.a, sub_ev.b);
Debug.Assert(sub_eid != NGonsCore.geometry3Sharp.mesh.DMesh3.InvalidID);
Debug.Assert(sub.SubMesh.IsBoundaryEdge(sub_eid));
cons.SetOrUpdateEdgeConstraint(sub_eid, EdgeConstraint.FullyConstrained);
cons.SetOrUpdateVertexConstraint(sub_ev.a, VertexConstraint.Pinned);
cons.SetOrUpdateVertexConstraint(sub_ev.b, VertexConstraint.Pinned);
}
}
