fixed how nodes are connected. We don't set empty cells at beginning and end anymore.

This however requires that we run the fix script after setting paths.

examples/flatland_2_0_example.py

@@ -32,15 +32,15 @@ speed_ration_map = {1.: 0.25,  # Fast passenger train
 
 env = RailEnv(width=50,
               height=50,
-              rail_generator=sparse_rail_generator(num_cities=10,  # Number of cities in map (where train stations are)
-                                                   num_intersections=0,  # Number of intersections (no start / target)
+              rail_generator=sparse_rail_generator(num_cities=5,  # Number of cities in map (where train stations are)
+                                                   num_intersections=4,  # Number of intersections (no start / target)
                                                    num_trainstations=100,  # Number of possible start/targets on map
                                                    min_node_dist=10,  # Minimal distance of nodes
                                                    node_radius=4,  # Proximity of stations to city center
-                                                   num_neighb=3,  # Number of connections to other cities/intersections
+                                                   num_neighb=2,  # Number of connections to other cities/intersections
                                                    seed=15,  # Random seed
                                                    grid_mode=True,
-                                                   nr_inter_connections=1,
+                                                   nr_inter_connections=2,
                                                    max_nr_connection_points=12
                                                    ),
               schedule_generator=sparse_schedule_generator(),

flatland/envs/grid4_generators_utils.py

@@ -45,7 +45,7 @@ def connect_basic_operation(
                     # need to flip direction because of how end points are defined
                     new_trans = rail_trans.set_transition(new_trans, mirror(current_dir), new_dir, 1)
                 else:
-                    new_trans = 0
+                    new_trans = rail_trans.set_transition(new_trans, current_dir, new_dir, 1)  # 0
             else:
                 # into existing rail
                 new_trans = rail_trans.set_transition(new_trans, current_dir, new_dir, 1)
@@ -65,7 +65,7 @@ def connect_basic_operation(
                 if flip_end_node_trans:
                     new_trans_e = rail_trans.set_transition(new_trans_e, new_dir, mirror(new_dir), 1)
                 else:
-                    new_trans_e = 0
+                    new_trans_e = rail_trans.set_transition(new_trans, current_dir, new_dir, 1)  #0
             else:
                 # into existing rail
                 new_trans_e = rail_trans.set_transition(new_trans_e, new_dir, new_dir, 1)