todo

src/bsp.rs

@@ -79,6 +79,7 @@ where
 				vertex_id
 			}).collect();
 			if face.is_visible(){
+				//TODO: deduplicate graphics groups by render id
 				graphics_groups.push(model::IndexedGraphicsGroup{
 					render:render_id,
 					groups:vec![polygon_group_id],