Add value-based equality for TriangleMesh

cpp/open3d/geometry/TriangleMesh.cpp

@@ -113,6 +113,21 @@ TriangleMesh TriangleMesh::operator+(const TriangleMesh &mesh) const {
     return (TriangleMesh(*this) += mesh);
 }
 
+bool TriangleMesh::operator==(const TriangleMesh &mesh) const {
+    if (vertices_.size() != mesh.vertices_.size()) return false;
+    if (triangles_.size() != mesh.triangles_.size()) return false;
+
+    for (unsigned long i = 0; i < vertices_.size(); ++i) {
+        if (!vertices_[i].isApprox(mesh.vertices_[i])) return false;
+    }
+
+    for (unsigned long i = 0; i < triangles_.size(); ++i) {
+        if (triangles_[i] != mesh.triangles_[i]) return false;
+    }
+
+    return true;
+}
+
 TriangleMesh &TriangleMesh::ComputeTriangleNormals(
         bool normalized /* = true*/) {
     triangle_normals_.resize(triangles_.size());

cpp/open3d/geometry/TriangleMesh.h

@@ -44,6 +44,21 @@ class TriangleMesh : public MeshBase {
                  const std::vector<Eigen::Vector3i> &triangles)
         : MeshBase(Geometry::GeometryType::TriangleMesh, vertices),
           triangles_(triangles) {}
+    /// \brief Copy Constructor.
+    ///
+    /// \param mesh other mesh to copy.
+    TriangleMesh(const TriangleMesh &mesh)
+        : MeshBase(Geometry::GeometryType::TriangleMesh, mesh.vertices_),
+          // vertex_normals_(mesh.vertex_normals_),
+          // vertex_colors_(mesh.vertex_colors_),
+          triangles_(mesh.triangles_),
+          triangle_normals_(mesh.triangle_normals_),
+          adjacency_list_(mesh.adjacency_list_),
+          triangle_uvs_(mesh.triangle_uvs_),
+          materials_(mesh.materials_),
+          triangle_material_ids_(mesh.triangle_material_ids_),
+          textures_(mesh.textures_) {}
+    TriangleMesh &operator=(const TriangleMesh &) = default;
     ~TriangleMesh() override {}
 
 public:
@@ -56,6 +71,7 @@ class TriangleMesh : public MeshBase {
 public:
     TriangleMesh &operator+=(const TriangleMesh &mesh);
     TriangleMesh operator+(const TriangleMesh &mesh) const;
+    bool operator==(const TriangleMesh &mesh) const;
 
     /// Returns `true` if the mesh contains triangles.
     bool HasTriangles() const {

cpp/pybind/geometry/trianglemesh.cpp

@@ -57,6 +57,7 @@ void pybind_trianglemesh_definitions(py::module &m) {
                  })
             .def(py::self + py::self)
             .def(py::self += py::self)
+            .def(py::self == py::self)
             .def("compute_triangle_normals",
                  &TriangleMesh::ComputeTriangleNormals,
                  "Function to compute triangle normals, usually called before "