make dummy obs at reset and use it

nmmo/core/env.py

@@ -2,6 +2,7 @@
 import random
 from typing import Any, Dict, List, Callable
 from collections import defaultdict
+from copy import copy
 from ordered_set import OrderedSet
 
 import gym
@@ -33,6 +34,7 @@ def __init__(self,
     self.config = config
     self.realm = realm.Realm(config)
     self.obs = None
+    self._dummy_obs = None
 
     self.possible_agents = list(range(1, config.PLAYER_N + 1))
     self._dead_agents = set()
@@ -157,6 +159,7 @@ def reset(self, map_id=None, seed=None, options=None,
       if isinstance(ent.agent, Scripted):
         self.scripted_agents.add(eid)
 
+    self._dummy_obs = self._make_dummy_obs()
     self.obs = self._compute_observations()
     self._gamestate_generator = GameStateGenerator(self.realm, self.config)
 
@@ -360,22 +363,26 @@ def _compute_scripted_agent_actions(self, actions: Dict[int, Dict[str, Dict[str,
 
     return actions
 
-  def _compute_observations(self):
-    '''Create an Observation object for each agent in self.agents'''
-    obs = {}
-    market = Item.Query.for_sale(self.realm.datastore) # the same for all agents
-
-    # dummy obs
+  def _make_dummy_obs(self):
     dummy_tiles = np.zeros((0, len(Tile.State.attr_name_to_col)))
     dummy_entities = np.zeros((0, len(Entity.State.attr_name_to_col)))
     dummy_inventory = np.zeros((0, len(Item.State.attr_name_to_col)))
     dummy_market = np.zeros((0, len(Item.State.attr_name_to_col)))
+    return Observation(self.config, self.realm.tick, 0,
+                       dummy_tiles, dummy_entities, dummy_inventory, dummy_market)
+
+  def _compute_observations(self):
+    '''Create an Observation object for each agent in self.agents'''
+    obs = {}
+    market = Item.Query.for_sale(self.realm.datastore) # the same for all agents
 
     for agent_id in self.agents:
       if agent_id not in self.realm.players:
         # return dummy obs for the agents in dead_this_tick
-        obs[agent_id] = Observation(self.config, self.realm.tick, agent_id,
-                                    dummy_tiles, dummy_entities, dummy_inventory, dummy_market)
+        dummy_obs = copy(self._dummy_obs)
+        dummy_obs.current_tick = self.realm.tick
+        dummy_obs.agent_id = agent_id
+        obs[agent_id] = dummy_obs
       else:
         agent = self.realm.players.get(agent_id)
         agent_r = agent.row.val