diff --git a/libs/phys/include/psemek/phys/engine_2d.hpp b/libs/phys/include/psemek/phys/engine_2d.hpp
index 47eba6ed..7d880283 100644
--- a/libs/phys/include/psemek/phys/engine_2d.hpp
+++ b/libs/phys/include/psemek/phys/engine_2d.hpp
@@ -7,6 +7,7 @@
 #include <psemek/geom/box.hpp>
 
 #include <memory>
+#include <variant>
 
 namespace psemek::phys2d
 {
@@ -46,9 +47,21 @@ namespace psemek::phys2d
 		static_state * group_static_state(group_handle handle);
 		dynamic_state * group_dynamic_state(group_handle handle);
 
-		void add_object(group_handle group, shape_handle shape, material_handle material, static_state const & ss, dynamic_state const & ds);
+		std::size_t add_object(group_handle group, shape_handle shape, material_handle material, static_state const & ss, dynamic_state const & ds);
 		void remove_object(group_handle group, std::size_t index);
 
+		struct object_info
+		{
+			engine::shape_handle shape;
+			engine::material_handle material;
+			float inv_mass;
+			float inv_inertia;
+		};
+
+		object_info const & info(group_handle group, std::size_t index);
+
+		std::variant<ball, half_space, box> shape(group_handle group, std::size_t index);
+
 		// Global system properties
 
 		void set_gravity(geom::vector<float, 2> const & g);
diff --git a/libs/phys/source/engine_2d.cpp b/libs/phys/source/engine_2d.cpp
index 470deb5b..a4df452a 100644
--- a/libs/phys/source/engine_2d.cpp
+++ b/libs/phys/source/engine_2d.cpp
@@ -369,14 +369,6 @@ namespace psemek::phys2d
 
 		util::flat_list<material, engine::material_handle> materials;
 
-		struct object_info
-		{
-			engine::shape_handle shape;
-			engine::material_handle material;
-			float inv_mass;
-			float inv_inertia;
-		};
-
 		struct group
 		{
 			std::vector<object_info> infos;
@@ -687,7 +679,7 @@ namespace psemek::phys2d
 		return impl().groups[handle].dynamic_states.data();
 	}
 
-	void engine::add_object(group_handle group, shape_handle shape, material_handle material, static_state const & ss, dynamic_state const & ds)
+	std::size_t engine::add_object(group_handle group, shape_handle shape, material_handle material, static_state const & ss, dynamic_state const & ds)
 	{
 		float const density = impl().materials[material].density;
 		float const area = impl().shapes.visit([](auto const & s){ return s.area; }, shape);
@@ -697,6 +689,8 @@ namespace psemek::phys2d
 		g.infos.push_back({shape, material, 1.f / (area * density), 1.f / (inertia * density)});
 		g.static_states.push_back(ss);
 		g.dynamic_states.push_back(ds);
+
+		return g.infos.size() - 1;
 	}
 
 	void engine::remove_object(group_handle group, std::size_t index)
@@ -707,6 +701,18 @@ namespace psemek::phys2d
 		g.dynamic_states.erase(g.dynamic_states.begin() + index);
 	}
 
+	engine::object_info const & engine::info(group_handle group, std::size_t index)
+	{
+		return impl().groups[group].infos[index];
+	}
+
+	std::variant<ball, half_space, box> engine::shape(group_handle group, std::size_t index)
+	{
+		using result = std::variant<ball, half_space, box>;
+		auto sh = impl().groups[group].infos[index].shape;
+		return impl().shapes.visit([](auto const & s) -> result { return s.shape; }, sh);
+	}
+
 	void engine::set_gravity(geom::vector<float, 2> const & g)
 	{
 		impl().gravity = g;