+/*
+ * Get the elements of a scene.
+ */
+list_t* scene_elements(const scene_t* s);
+
+/*
+ * Get the lights of a scene.
+ */
+list_t* scene_lights(const scene_t* s);
+
+/*
+ * Get the ambient light color of the scene.
+ */
+color_t scene_ambient(const scene_t* s);
+
+