Add Support for Nonmanifold Smooth Edges

src/ipc/collision_mesh.cpp

@@ -135,19 +135,10 @@ void CollisionMesh::init_edges_to_faces()
         return;
     }
 
-    m_edges_to_faces.setConstant(num_edges(), 2, -1);
+    m_edges_to_faces.resize(num_edges());
     for (int f = 0; f < m_faces_to_edges.rows(); f++) {
         for (int le = 0; le < 3; le++) {
-            if (m_edges_to_faces(m_faces_to_edges(f, le), 0) < 0) {
-                m_edges_to_faces(m_faces_to_edges(f, le), 0) = f;
-            } else if (m_edges_to_faces(m_faces_to_edges(f, le), 1) < 0) {
-                m_edges_to_faces(m_faces_to_edges(f, le), 1) = f;
-            } else {
-                logger().warn(
-                    "Edge {} of face {} is shared by more than 2 faces. "
-                    "This may cause issues with the Geometric Contact Potential (smooth contact).",
-                    m_faces_to_edges(f, le), f);
-            }
+            m_edges_to_faces[m_faces_to_edges(f, le)].push_back(f);
         }
     }
 }

src/ipc/collision_mesh.hpp

@@ -142,8 +142,13 @@ class CollisionMesh {
         return m_vertices_to_faces;
     }
 
-    /// @brief Get the mapping from edges to faces of the collision mesh (|E| × 2).
-    const Eigen::MatrixXi& edges_to_faces() const { return m_edges_to_faces; }
+    /// @brief Get the mapping from edges to faces of the collision mesh.
+    /// @return A vector of size |E|, where each entry is a vector of face
+    /// indices adjacent to that edge.
+    const std::vector<std::vector<index_t>>& edges_to_faces() const
+    {
+        return m_edges_to_faces;
+    }
 
     // -----------------------------------------------------------------------
 
@@ -340,7 +345,7 @@ class CollisionMesh {
     // -----------------------------------------------------------------------
     // Helper initialization functions
 
-    /// @brief Initialize map from edges to adjacent faces (|E| × 2).
+    /// @brief Initialize map from edges to adjacent faces.
     void init_edges_to_faces();
 
     /// @brief Initialize the codimensional vertices.
@@ -377,8 +382,8 @@ class CollisionMesh {
     Eigen::MatrixXi m_faces;
     /// @brief Map from faces edges to rows of edges (|F| × 3).
     Eigen::MatrixXi m_faces_to_edges;
-    /// @brief Map from edges to adjacent faces (|E| × 2).
-    Eigen::MatrixXi m_edges_to_faces;
+    /// @brief Map from edges to adjacent faces (|E| entries, variable length).
+    std::vector<std::vector<index_t>> m_edges_to_faces;
 
     /// @brief Map from full vertices to collision vertices.
     /// @note Negative values indicate full vertex is dropped.

src/ipc/smooth_contact/common.hpp

@@ -10,7 +10,7 @@ static constexpr int N_EDGE_NEIGHBORS_2D = 2;
 static constexpr int MAX_VERT_2D =
     2 * std::max(N_VERT_NEIGHBORS_2D, N_EDGE_NEIGHBORS_2D);
 static constexpr int N_VERT_NEIGHBORS_3D = 20; // increase me if needed
-static constexpr int N_EDGE_NEIGHBORS_3D = 4;
+static constexpr int N_EDGE_NEIGHBORS_3D = 6;  // increase me if needed
 static constexpr int N_FACE_NEIGHBORS_3D = 3;
 static constexpr int MAX_VERT_3D = N_VERT_NEIGHBORS_3D * 2;
 

src/ipc/smooth_contact/distance/point_edge.cpp

@@ -325,6 +325,9 @@ template class PointEdgeDistance<ADGrad<18>, 3>;
 template class PointEdgeDistance<ADHessian<18>, 3>;
 #endif
 
+template class PointEdgeDistance<ADGrad<Eigen::Dynamic>, 3>;
+template class PointEdgeDistance<ADHessian<Eigen::Dynamic>, 3>;
+
 template class PointEdgeDistanceDerivatives<2>;
 template class PointEdgeDistanceDerivatives<3>;
 } // namespace ipc

src/ipc/smooth_contact/primitives/CMakeLists.txt

@@ -1,6 +1,4 @@
 set(SOURCES
-  autogen.cpp
-  autogen.hpp
   edge2.cpp
   edge2.hpp
   edge3.cpp