Implemented GoToDoor environment

gym_minigrid/envs/__init__.py

@@ -3,4 +3,5 @@ from gym_minigrid.envs.doorkey import *
 from gym_minigrid.envs.multiroom import *
 from gym_minigrid.envs.fetch import *
 from gym_minigrid.envs.gotoobject import *
+from gym_minigrid.envs.gotodoor import *
 from gym_minigrid.envs.fourroomqa import *

gym_minigrid/envs/gotodoor.py

@@ -0,0 +1,114 @@
+from gym_minigrid.minigrid import *
+from gym_minigrid.register import register
+
+class GoToDoorEnv(MiniGridEnv):
+    """
+    Environment in which the agent is instructed to go to a given object
+    named using an English text string
+    """
+
+    def __init__(
+        self,
+        size=5
+    ):
+        super().__init__(gridSize=size, maxSteps=10*size)
+
+        self.reward_range = (-1, self.maxSteps)
+
+    def _genGrid(self, width, height):
+        assert width == height
+
+        # Randomize the player start position and orientation
+        self.startPos = self._randPos(
+            1, width-1,
+            1, height-1
+        )
+        self.startDir = self._randInt(0, 4)
+
+        # Create a grid surrounded by walls
+        grid = Grid(width, height)
+        for i in range(0, width):
+            grid.set(i, 0, Wall())
+            grid.set(i, height-1, Wall())
+        for j in range(0, height):
+            grid.set(0, j, Wall())
+            grid.set(width-1, j, Wall())
+
+        colors = list(COLORS.keys())
+
+        # Generate the 4 doors at random positions
+        doorPos = []
+        doorPos.append((self._randInt(2, width-2), 0))
+        doorPos.append((self._randInt(2, width-2), height-1))
+        doorPos.append((0, self._randInt(2, height-2)))
+        doorPos.append((width-1, self._randInt(2, height-2)))
+
+        # Generate the door colors
+        doorColors = []
+        while len(doorColors) < len(doorPos):
+            color = self._randElem(colors)
+            if color in doorColors:
+                continue
+            doorColors.append(color)
+
+        # Place the doors in the grid
+        for idx, pos in enumerate(doorPos):
+            color = doorColors[idx]
+            grid.set(*pos, Door(color))
+
+        # Select a random target door
+        doorIdx = self._randInt(0, len(doorPos))
+        self.targetPos = doorPos[idx]
+        self.targetColor = doorColors[idx]
+
+        # Generate the mission string
+        self.mission = 'go to the %s door' % self.targetColor
+        #print(self.mission)
+
+        return grid
+
+    def _observation(self, obs):
+        """
+        Encode observations
+        """
+
+        obs = {
+            'image': obs,
+            'mission': self.mission,
+            'advice' : ''
+        }
+
+        return obs
+
+    def _reset(self):
+        obs = MiniGridEnv._reset(self)
+        return self._observation(obs)
+
+    def _step(self, action):
+        obs, reward, done, info = MiniGridEnv._step(self, action)
+
+        ax, ay = self.agentPos
+        tx, ty = self.targetPos
+
+        # Don't let the agent open any of the doors
+        if action == self.actions.toggle:
+            done = True
+            reward = -1
+
+        # Reward waiting in front of the target door
+        if action == self.actions.wait:
+            if ax == tx and abs(ay - ty) == 1:
+                reward = 1
+            elif ay == ty and abs(ax - tx) == 1:
+                reward = 1
+            #else:
+            #    reward = -0.1
+
+        obs = self._observation(obs)
+
+        return obs, reward, done, info
+
+register(
+    id='MiniGrid-GoToDoor-5x5-v0',
+    entry_point='gym_minigrid.envs:GoToDoorEnv'
+)