public CollisionFlags getObstacles() {
		if (base == null) {
			base = Game.getMapBase();
			obs = null;
		}
		if (obs != null) {
			if (obs instanceof ObjectCollisionFlags) {
				((ObjectCollisionFlags) obs).loadObjects();
			}
			return obs;
		}
		if (objIds != null) {
			return obs = new ObjectCollisionFlags(base, objIds);
		} else {
			return obs = new CollisionFlags(base);
		}
	}