added TODO: Tree Observation needs to be adjusted to new transition possibilities.

examples/training_navigation.py

@@ -30,13 +30,13 @@ env = RailEnv(width=20,
               rail_generator=complex_rail_generator(nr_start_goal=20, min_dist=10, max_dist=99999, seed=0),
               number_of_agents=5)
 
-"""
+
 env = RailEnv(width=20,
               height=20,
               rail_generator=rail_from_list_of_saved_GridTransitionMap_generator(
                   ['../env-data/tests/circle.npy']),
               number_of_agents=1)
-
+"""
 
 env_renderer = RenderTool(env, gl="QT")
 handle = env.get_agent_handles()
@@ -109,7 +109,7 @@ for trials in range(1, n_trials + 1):
         for a in range(env.number_of_agents):
             if demo:
                 eps = 0
-            action = 2 #agent.act(np.array(obs[a]), eps=eps)
+            action = agent.act(np.array(obs[a]), eps=eps)
             action_prob[action] += 1
             action_dict.update({a: action})
             #env.obs_builder.util_print_obs_subtree(tree=obs[a], num_features_per_node=5)

flatland/core/env_observation_builder.py

@@ -243,6 +243,7 @@ class TreeObsForRailEnv(ObservationBuilder):
 
         # Start from the current orientation, and see which transitions are available;
         # organize them as [left, forward, right, back], relative to the current orientation
+        # TODO: Adjust this to the novel movement dynamics --> Only Forward present when one transition is possible.
         for branch_direction in [(orientation + 4 + i) % 4 for i in range(-1, 3)]:
             if self.env.rail.get_transition((position[0], position[1], orientation), branch_direction):
                 new_cell = self._new_position(position, branch_direction)
@@ -342,8 +343,8 @@ class TreeObsForRailEnv(ObservationBuilder):
 
             elif num_transitions == 0:
                 # Wrong cell type, but let's cover it and treat it as a dead-end, just in case
-                #print("WRONG CELL TYPE detected in tree-search (0 transitions possible) at cell", position[0],
-                #      position[1], direction)
+                print("WRONG CELL TYPE detected in tree-search (0 transitions possible) at cell", position[0],
+                      position[1], direction)
                 last_isTerminal = True
                 break