Fix bug in Instance Cam

metadrive/engine/base_engine.py

@@ -21,20 +21,18 @@
 
 
 def generate_distinct_rgb_values():
-    r = np.linspace(0, 256, 16)
-    g = np.linspace(0, 256, 16)
-    b = np.linspace(0, 256, 16)
+    # Try to avoid (0,0,0) and (255,255,255) to avoid confusion with the background and other objects.
+    r = np.linspace(16, 256 - 16, 16).astype(int)
+    g = np.linspace(16, 256 - 16, 16).astype(int)
+    b = np.linspace(16, 256 - 16, 16).astype(int)
 
     # Create a meshgrid and reshape to get all combinations of r, g, b
     rgbs = np.array(np.meshgrid(r, g, b)).T.reshape(-1, 3)
 
     # Normalize the values to be between 0 and 1
     rgbs = rgbs / 255.0
 
-    # Round to 5 decimal places to avoid floating point errors
-    rgbs = np.round(rgbs, 5)
-
-    return tuple(tuple(v) for v in rgbs.tolist())
+    return tuple(tuple(round(vv, 5) for vv in v) for v in rgbs)
 
 
 COLOR_SPACE = generate_distinct_rgb_values()

metadrive/tests/test_sensors/test_instance_cam.py

@@ -42,7 +42,7 @@ def test_instance_cam(config, render=False):
         env.reset()
         base_free = len(env.engine.COLORS_FREE)
         base_occupied = len(env.engine.COLORS_OCCUPIED)
-        assert base_free + base_occupied == 4096
+        assert base_free + base_occupied == env.engine.MAX_COLOR
         import cv2
         import time
         start = time.time()
@@ -76,7 +76,7 @@ def test_instance_cam(config, render=False):
                     assert env.engine.id_c[env.engine.c_id[color]] == color  #Making sure the color-id is a bijection
                     assert len(env.engine.c_id.keys()) == len(env.engine.COLORS_OCCUPIED)
                     assert len(env.engine.id_c.keys()) == len(env.engine.COLORS_OCCUPIED)
-                    assert len(env.engine.COLORS_FREE) + len(env.engine.COLORS_OCCUPIED) == 4096
+                    assert len(env.engine.COLORS_FREE) + len(env.engine.COLORS_OCCUPIED) == env.engine.MAX_COLOR
             #Making sure every object in the engine(not necessarily observable) have corresponding color
             for id, object in env.engine.get_objects().items():
                 assert id in env.engine.id_c.keys()