world model physics groups

world models are not guaranteed to be convex, so this is problematic for physics

lib/bsp_loader/src/bsp.rs

@@ -194,7 +194,11 @@ pub fn convert<'a>(
 			model::PolygonGroup::PolygonList(model::PolygonList::new(polygon_list))
 		}).collect();
 
-		mb.build(polygon_groups,graphics_groups,vec![])
+		let physics_groups=vec![model::IndexedPhysicsGroup{
+			groups:(0..world_model.face_count as u32).map(model::PolygonGroupId::new).collect(),
+		}];
+
+		mb.build(polygon_groups,graphics_groups,physics_groups)
 	}).collect();
 
 	let mut found_spawn=None;