Supports rl games wrapper with dictionary observation (#3340)

# Description

This PR opens the possibility to use dictionary observation for rl-games
application.
This benefits:
1. combination of high + low dim observations percolate into actor and
critic in rl-games
2. avoid double computation if actor and critic share the same
observation


## Type of change

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applicable. -->

- New feature (non-breaking change which adds functionality)

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## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

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scripts/reinforcement_learning/rl_games/play.py

@@ -134,6 +134,8 @@ def main(env_cfg: ManagerBasedRLEnvCfg | DirectRLEnvCfg | DirectMARLEnvCfg, agen
     rl_device = agent_cfg["params"]["config"]["device"]
     clip_obs = agent_cfg["params"]["env"].get("clip_observations", math.inf)
     clip_actions = agent_cfg["params"]["env"].get("clip_actions", math.inf)
+    obs_groups = agent_cfg["params"]["env"].get("obs_groups")
+    concate_obs_groups = agent_cfg["params"]["env"].get("concate_obs_groups", True)
 
     # create isaac environment
     env = gym.make(args_cli.task, cfg=env_cfg, render_mode="rgb_array" if args_cli.video else None)
@@ -155,7 +157,7 @@ def main(env_cfg: ManagerBasedRLEnvCfg | DirectRLEnvCfg | DirectMARLEnvCfg, agen
         env = gym.wrappers.RecordVideo(env, **video_kwargs)
 
     # wrap around environment for rl-games
-    env = RlGamesVecEnvWrapper(env, rl_device, clip_obs, clip_actions)
+    env = RlGamesVecEnvWrapper(env, rl_device, clip_obs, clip_actions, obs_groups, concate_obs_groups)
 
     # register the environment to rl-games registry
     # note: in agents configuration: environment name must be "rlgpu"

scripts/reinforcement_learning/rl_games/train.py

@@ -148,6 +148,8 @@ def main(env_cfg: ManagerBasedRLEnvCfg | DirectRLEnvCfg | DirectMARLEnvCfg, agen
     rl_device = agent_cfg["params"]["config"]["device"]
     clip_obs = agent_cfg["params"]["env"].get("clip_observations", math.inf)
     clip_actions = agent_cfg["params"]["env"].get("clip_actions", math.inf)
+    obs_groups = agent_cfg["params"]["env"].get("obs_groups")
+    concate_obs_groups = agent_cfg["params"]["env"].get("concate_obs_groups", True)
 
     # set the IO descriptors output directory if requested
     if isinstance(env_cfg, ManagerBasedRLEnvCfg):
@@ -178,7 +180,7 @@ def main(env_cfg: ManagerBasedRLEnvCfg | DirectRLEnvCfg | DirectMARLEnvCfg, agen
         env = gym.wrappers.RecordVideo(env, **video_kwargs)
 
     # wrap around environment for rl-games
-    env = RlGamesVecEnvWrapper(env, rl_device, clip_obs, clip_actions)
+    env = RlGamesVecEnvWrapper(env, rl_device, clip_obs, clip_actions, obs_groups, concate_obs_groups)
 
     # register the environment to rl-games registry
     # note: in agents configuration: environment name must be "rlgpu"

source/isaaclab_rl/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.2.4"
+version = "0.3.0"
 
 # Description
 title = "Isaac Lab RL"

source/isaaclab_rl/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.3.0 (2025-09-03)
+~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Enhanced rl-games wrapper to allow dict observation.
+
+
 0.2.4 (2025-08-07)
 ~~~~~~~~~~~~~~~~~~
 

source/isaaclab_rl/isaaclab_rl/rl_games.py

@@ -37,6 +37,7 @@ from __future__ import annotations
 import gym.spaces  # needed for rl-games incompatibility: https://github.com/Denys88/rl_games/issues/261
 import gymnasium
 import torch
+from collections.abc import Callable
 
 from rl_games.common import env_configurations
 from rl_games.common.vecenv import IVecEnv
@@ -60,12 +61,14 @@ class RlGamesVecEnvWrapper(IVecEnv):
     observations. This dictionary contains "obs" and "states" which typically correspond
     to the actor and critic observations respectively.
 
-    To use asymmetric actor-critic, the environment observations from :class:`ManagerBasedRLEnv` or :class:`DirectRLEnv`
-    must have the key or group name "critic". The observation group is used to set the
-    :attr:`num_states` (int) and :attr:`state_space` (:obj:`gym.spaces.Box`). These are
-    used by the learning agent in RL-Games to allocate buffers in the trajectory memory.
-    Since this is optional for some environments, the wrapper checks if these attributes exist.
-    If they don't then the wrapper defaults to zero as number of privileged observations.
+    To use asymmetric actor-critic, map privileged observation groups under ``"states"`` (e.g. ``["critic"]``).
+
+    The wrapper supports **either** concatenated tensors (default) **or** Dict inputs:
+    when wrapper is concate mode, rl-games sees {"obs": Tensor, (optional)"states": Tensor}
+    when wrapper is not concate mode, rl-games sees {"obs": dict[str, Tensor], (optional)"states": dict[str, Tensor]}
+    - Concatenated mode (``concate_obs_group=True``): ``observation_space``/``state_space`` are ``gym.spaces.Box``.
+    - Dict mode (``concate_obs_group=False``): ``observation_space``/``state_space`` are ``gym.spaces.Dict`` keyed by
+      the requested groups. When no ``"states"`` groups are provided, the states Dict is omitted at runtime.
 
     .. caution::
 
@@ -79,7 +82,15 @@ class RlGamesVecEnvWrapper(IVecEnv):
         https://github.com/NVIDIA-Omniverse/IsaacGymEnvs
     """
 
-    def __init__(self, env: ManagerBasedRLEnv | DirectRLEnv, rl_device: str, clip_obs: float, clip_actions: float):
+    def __init__(
+        self,
+        env: ManagerBasedRLEnv | DirectRLEnv,
+        rl_device: str,
+        clip_obs: float,
+        clip_actions: float,
+        obs_groups: dict[str, list[str]] | None = None,
+        concate_obs_group: bool = True,
+    ):
         """Initializes the wrapper instance.
 
         Args:
@@ -87,6 +98,9 @@ class RlGamesVecEnvWrapper(IVecEnv):
             rl_device: The device on which agent computations are performed.
             clip_obs: The clipping value for observations.
             clip_actions: The clipping value for actions.
+            obs_groups: The remapping from isaaclab observation to rl-games, default to None for backward compatible.
+            concate_obs_group: The boolean value indicates if input to rl-games network is dict or tensor. Default to
+                True for backward compatible.
 
         Raises:
             ValueError: The environment is not inherited from :class:`ManagerBasedRLEnv` or :class:`DirectRLEnv`.
@@ -105,11 +119,36 @@ class RlGamesVecEnvWrapper(IVecEnv):
         self._clip_obs = clip_obs
         self._clip_actions = clip_actions
         self._sim_device = env.unwrapped.device
-        # information for privileged observations
-        if self.state_space is None:
-            self.rlg_num_states = 0
-        else:
+
+        # resolve the observation group
+        self._concate_obs_groups = concate_obs_group
+        self._obs_groups = obs_groups
+        if obs_groups is None:
+            self._obs_groups = {"obs": ["policy"], "states": []}
+            if not self.unwrapped.single_observation_space.get("policy"):
+                raise KeyError("Policy observation group is expected if no explicit groups is defined")
+            if self.unwrapped.single_observation_space.get("critic"):
+                self._obs_groups["states"] = ["critic"]
+
+        if (
+            self._concate_obs_groups
+            and isinstance(self.state_space, gym.spaces.Box)
+            and isinstance(self.observation_space, gym.spaces.Box)
+        ):
             self.rlg_num_states = self.state_space.shape[0]
+        elif (
+            not self._concate_obs_groups
+            and isinstance(self.state_space, gym.spaces.Dict)
+            and isinstance(self.observation_space, gym.spaces.Dict)
+        ):
+            space = [space.shape[0] for space in self.state_space.values()]
+            self.rlg_num_states = sum(space)
+        else:
+            raise TypeError(
+                "only valid combination for state space is gym.space.Box when concate_obs_groups is True,             "
+                "   and gym.space.Dict when concate_obs_groups is False. You have concate_obs_groups:                "
+                f" {self._concate_obs_groups}, and state_space: {self.state_space.__class__}"
+            )
 
     def __str__(self):
         """Returns the wrapper name and the :attr:`env` representation string."""
@@ -135,19 +174,18 @@ class RlGamesVecEnvWrapper(IVecEnv):
         return self.env.render_mode
 
     @property
-    def observation_space(self) -> gym.spaces.Box:
-        """Returns the :attr:`Env` :attr:`observation_space`."""
+    def observation_space(self) -> gym.spaces.Box | gym.spaces.Dict:
+        """Returns the :attr:`Env` :attr:`observation_space` (``Box`` if concatenated, otherwise ``Dict``)."""
         # note: rl-games only wants single observation space
-        policy_obs_space = self.unwrapped.single_observation_space["policy"]
-        if not isinstance(policy_obs_space, gymnasium.spaces.Box):
-            raise NotImplementedError(
-                f"The RL-Games wrapper does not currently support observation space: '{type(policy_obs_space)}'."
-                f" If you need to support this, please modify the wrapper: {self.__class__.__name__},"
-                " and if you are nice, please send a merge-request."
-            )
-        # note: maybe should check if we are a sub-set of the actual space. don't do it right now since
-        #   in ManagerBasedRLEnv we are setting action space as (-inf, inf).
-        return gym.spaces.Box(-self._clip_obs, self._clip_obs, policy_obs_space.shape)
+        space = self.unwrapped.single_observation_space
+        clip = self._clip_obs
+        if not self._concate_obs_groups:
+            policy_space = {grp: gym.spaces.Box(-clip, clip, space.get(grp).shape) for grp in self._obs_groups["obs"]}
+            return gym.spaces.Dict(policy_space)
+        else:
+            shapes = [space.get(group).shape for group in self._obs_groups["obs"]]
+            cat_shape, self._obs_concat_fn = make_concat_plan(shapes)
+            return gym.spaces.Box(-clip, clip, cat_shape)
 
     @property
     def action_space(self) -> gym.Space:
@@ -193,23 +231,18 @@ class RlGamesVecEnvWrapper(IVecEnv):
         return self.unwrapped.device
 
     @property
-    def state_space(self) -> gym.spaces.Box | None:
-        """Returns the :attr:`Env` :attr:`observation_space`."""
-        # note: rl-games only wants single observation space
-        critic_obs_space = self.unwrapped.single_observation_space.get("critic")
-        # check if we even have a critic obs
-        if critic_obs_space is None:
-            return None
-        elif not isinstance(critic_obs_space, gymnasium.spaces.Box):
-            raise NotImplementedError(
-                f"The RL-Games wrapper does not currently support state space: '{type(critic_obs_space)}'."
-                f" If you need to support this, please modify the wrapper: {self.__class__.__name__},"
-                " and if you are nice, please send a merge-request."
-            )
-        # return casted space in gym.spaces.Box (OpenAI Gym)
-        # note: maybe should check if we are a sub-set of the actual space. don't do it right now since
-        #   in ManagerBasedRLEnv we are setting action space as (-inf, inf).
-        return gym.spaces.Box(-self._clip_obs, self._clip_obs, critic_obs_space.shape)
+    def state_space(self) -> gym.spaces.Box | gym.spaces.Dict | None:
+        """Returns the privileged observation space for the critic (``Box`` if concatenated, otherwise ``Dict``)."""
+        # # note: rl-games only wants single observation space
+        space = self.unwrapped.single_observation_space
+        clip = self._clip_obs
+        if not self._concate_obs_groups:
+            state_space = {grp: gym.spaces.Box(-clip, clip, space.get(grp).shape) for grp in self._obs_groups["states"]}
+            return gym.spaces.Dict(state_space)
+        else:
+            shapes = [space.get(group).shape for group in self._obs_groups["states"]]
+            cat_shape, self._states_concat_fn = make_concat_plan(shapes)
+            return gym.spaces.Box(-self._clip_obs, self._clip_obs, cat_shape)
 
     def get_number_of_agents(self) -> int:
         """Returns number of actors in the environment."""
@@ -270,7 +303,7 @@ class RlGamesVecEnvWrapper(IVecEnv):
     Helper functions
     """
 
-    def _process_obs(self, obs_dict: VecEnvObs) -> torch.Tensor | dict[str, torch.Tensor]:
+    def _process_obs(self, obs_dict: VecEnvObs) -> dict[str, torch.Tensor] | dict[str, dict[str, torch.Tensor]]:
         """Processing of the observations and states from the environment.
 
         Note:
@@ -280,32 +313,61 @@ class RlGamesVecEnvWrapper(IVecEnv):
         Args:
             obs_dict: The current observations from environment.
 
-        Returns:
-            If environment provides states, then a dictionary containing the observations and states is returned.
-            Otherwise just the observations tensor is returned.
+         Returns:
+            A dictionary for RL-Games with keys:
+            - ``"obs"``: either a concatenated tensor (``concate_obs_group=True``) or a Dict of group tensors.
+            - ``"states"`` (optional): same structure as above when state groups are configured; omitted otherwise.
         """
-        # process policy obs
-        obs = obs_dict["policy"]
         # clip the observations
-        obs = torch.clamp(obs, -self._clip_obs, self._clip_obs)
-        # move the buffer to rl-device
-        obs = obs.to(device=self._rl_device).clone()
-
-        # check if asymmetric actor-critic or not
-        if self.rlg_num_states > 0:
-            # acquire states from the environment if it exists
-            try:
-                states = obs_dict["critic"]
-            except AttributeError:
-                raise NotImplementedError("Environment does not define key 'critic' for privileged observations.")
-            # clip the states
-            states = torch.clamp(states, -self._clip_obs, self._clip_obs)
-            # move buffers to rl-device
-            states = states.to(self._rl_device).clone()
-            # convert to dictionary
-            return {"obs": obs, "states": states}
+        for key, obs in obs_dict.items():
+            obs_dict[key] = torch.clamp(obs, -self._clip_obs, self._clip_obs)
+
+        # process input obs dict
+        rl_games_obs = {"obs": {group: obs_dict[group] for group in self._obs_groups["obs"]}}
+        if len(self._obs_groups["states"]) > 0:
+            rl_games_obs["states"] = {group: obs_dict[group] for group in self._obs_groups["states"]}
+
+        if self._concate_obs_groups:
+            rl_games_obs["obs"] = self._obs_concat_fn(list(rl_games_obs["obs"].values()))
+            if "states" in rl_games_obs:
+                rl_games_obs["states"] = self._states_concat_fn(list(rl_games_obs["states"].values()))
+
+        return rl_games_obs
+
+
+def make_concat_plan(shapes: list[tuple[int, ...]]) -> tuple[tuple[int, ...], Callable]:
+    """
+    Given per-sample shapes (no batch dim), return:
+      - the concatenated per-sample shape
+      - a function that concatenates a list of batch tensors accordingly.
+
+    Rules:
+      0) Empty -> (0,), No-op
+      1) All 1D -> concat features (dim=1).
+      2) Same rank > 1:
+         2a) If all s[:-1] equal -> concat along last dim (channels-last, dim=-1).
+         2b) If all s[1:] equal  -> concat along first dim (channels-first, dim=1).
+    """
+    if len(shapes) == 0:
+        return (0,), lambda x: x
+    # case 1: all vectors
+    if all(len(s) == 1 for s in shapes):
+        return (sum(s[0] for s in shapes),), lambda x: torch.cat(x, dim=1)
+    # case 2: same rank > 1
+    rank = len(shapes[0])
+    if all(len(s) == rank for s in shapes) and rank > 1:
+        # 2a: concat along last axis (…C)
+        if all(s[:-1] == shapes[0][:-1] for s in shapes):
+            out_shape = shapes[0][:-1] + (sum(s[-1] for s in shapes),)
+            return out_shape, lambda x: torch.cat(x, dim=-1)
+        # 2b: concat along first axis (C…)
+        if all(s[1:] == shapes[0][1:] for s in shapes):
+            out_shape = (sum(s[0] for s in shapes),) + shapes[0][1:]
+            return out_shape, lambda x: torch.cat(x, dim=1)
         else:
-            return obs
+            raise ValueError(f"Could not find a valid concatenation plan for rank {[(len(s),) for s in shapes]}")
+    else:
+        raise ValueError("Could not find a valid concatenation plan, please make sure all value share the same size")
 
 
 """