decrease optical size of levels

@adrian please fix visuals.. ,)

flatland/envs/generators.py

@@ -842,6 +842,7 @@ def sparse_rail_generator(num_cities=100, num_intersections=10, num_trainstation
         node_positions = []
         city_positions = []
         intersection_positions = []
+
         for node_idx in range(num_cities + num_intersections):
             to_close = True
             tries = 0

flatland/utils/graphics_pil.py

@@ -52,10 +52,10 @@ class PILGL(GraphicsLayer):
         self.background_grid = np.zeros(shape=(self.width, self.height))
 
         if jupyter is False:
-            # NOTE: Currently removed the dependency on 
-            #       screeninfo. We have to find an alternate 
+            # NOTE: Currently removed the dependency on
+            #       screeninfo. We have to find an alternate
             #       way to compute the screen width and height
-            #       In the meantime, we are harcoding the 800x600 
+            #       In the meantime, we are harcoding the 800x600
             #       assumption
             self.screen_width = 800
             self.screen_height = 600
@@ -114,7 +114,7 @@ class PILGL(GraphicsLayer):
                     for rc in dTargets:
                         r = rc[1]
                         c = rc[0]
-                        d = int(np.floor(np.sqrt((x - r) ** 2 + (y - c) ** 2)))
+                        d = int(np.floor(np.sqrt((x - r) ** 2 + (y - c) ** 2)) / 0.5)
                         distance = min(d, distance)
                     self.background_grid[x][y] = distance
 
@@ -444,7 +444,7 @@ class PILSVG(PILGL):
 
         for transition, file in file_directory.items():
 
-            # Translate the ascii transition description in the format  "NE WS" to the 
+            # Translate the ascii transition description in the format  "NE WS" to the
             # binary list of transitions as per RailEnv - NESW (in) x NESW (out)
             transition_16_bit = ["0"] * 16
             for sTran in transition.split(" "):

tests/test_flatland_env_sparse_rail_generator.py

@@ -25,15 +25,15 @@ def test_realistic_rail_generator():
 def test_sparse_rail_generator():
     env = RailEnv(width=50,
                   height=50,
-                  rail_generator=sparse_rail_generator(num_cities=2,  # Number of cities in map
-                                                       num_intersections=3,  # Number of interesections in map
-                                                       num_trainstations=5,  # Number of possible start/targets on map
-                                                       min_node_dist=10,  # Minimal distance of nodes
-                                                       node_radius=2,  # Proximity of stations to city center
-                                                       num_neighb=3,  # Number of connections to other cities
+                  rail_generator=sparse_rail_generator(num_cities=3,  # Number of cities in map
+                                                       num_intersections=2,  # Number of interesections in map
+                                                       num_trainstations=15,  # Number of possible start/targets on map
+                                                       min_node_dist=6,  # Minimal distance of nodes
+                                                       node_radius=3,  # Proximity of stations to city center
+                                                       num_neighb=2,  # Number of connections to other cities
                                                        seed=5,  # Random seed
                                                        ),
-                  number_of_agents=0,
+                  number_of_agents=10,
                   obs_builder_object=GlobalObsForRailEnv())
     # reset to initialize agents_static
     env_renderer = RenderTool(env, gl="PILSVG", )