fix serialization for PrimitiveObject, initialize visual markers for …

…nav task

igibson/objects/primitive_object.py

@@ -356,3 +356,12 @@ def _deserialize(self, state):
         state_dict["height"] = state[idx + 1]
         state_dict["size"] = state[idx + 2]
         return state_dict, idx + 3
+
+    def _serialize(self, state):
+        # Run super first
+        state_flat = super()._serialize(state=state)
+
+        return np.concatenate([
+            state_flat,
+            np.array([state["radius"], state["height"], state["size"]]),
+        ])

igibson/tasks/point_navigation_task.py

@@ -193,6 +193,9 @@ def _load_visualization_markers(self, env):
             # Store waypoints
             self._waypoint_markers = waypoints
 
+        # Take one sim step to initialize all the markers
+        ig.sim.step()
+
     def _sample_initial_pose_and_goal_pos(self, env, max_trials=100):
         """
         Potentially sample the robot initial pos / ori and target pos, based on whether we're using randomized