Fixes ObservationManager history buffer corrupted by external calls to...

Fixes ObservationManager history buffer corrupted by external calls to ObservationManager.compute (#2885)

# Description

When observation group has history length greater than zero, calling
`ObservationManager.compute` modifies history state by appending current
observation to history. This creates history corruption when
non-`ManagerBasedEnv` classes invoke `ObservationManager.compute`. This
PR introduces `update_history` flag (default to `False`) and only
`ManagerBasedEnv` has the privilege to run `ObservationManager.compute`
with `update_history=True`. If `update_history=False` and the history
buffer is `None`, a copy of history is returned instead of the original.

I have added test cases to verify this fix is effective.

Fixes #2884 

## Type of change

- Bug fix (non-breaking change which fixes an issue)

## 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
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] 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

---------
Signed-off-by: ooctipus <zhengyuz@nvidia.com>
Signed-off-by: Kelly Guo <kellyg@nvidia.com>
Co-authored-by: ooctipus <zhengyuz@nvidia.com>
Co-authored-by: Kelly Guo <kellyg@nvidia.com>

CONTRIBUTORS.md

@@ -97,6 +97,7 @@ Guidelines for modifications:
 * Ori Gadot
 * Oyindamola Omotuyi
 * Özhan Özen
+* Patrick Yin
 * Peter Du
 * Pulkit Goyal
 * Qian Wan

source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.40.17"
+version = "0.40.18"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.40.18 (2025-07-09)
+~~~~~~~~~~~~~~~~~~~~
+
+Added
+^^^^^
+
+* Added input param ``update_history`` to :meth:`~isaaclab.managers.ObservationManager.compute`
+  to control whether the history buffer should be updated.
+* Added unit test for :class:`~isaaclab.envs.ManagerBasedEnv`.
+
+Fixed
+^^^^^
+
+* Fixed :class:`~isaaclab.envs.ManagerBasedEnv` and :class:`~isaaclab.envs.ManagerBasedRLEnv` to not update the history
+  buffer on recording.
+
+
 0.40.17 (2025-07-10)
 ~~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/envs/manager_based_env.py

@@ -305,7 +305,7 @@ class ManagerBasedEnv:
         self.recorder_manager.record_post_reset(env_ids)
 
         # compute observations
-        self.obs_buf = self.observation_manager.compute()
+        self.obs_buf = self.observation_manager.compute(update_history=True)
 
         if self.cfg.wait_for_textures and self.sim.has_rtx_sensors():
             while SimulationManager.assets_loading():
@@ -365,7 +365,7 @@ class ManagerBasedEnv:
         self.recorder_manager.record_post_reset(env_ids)
 
         # compute observations
-        self.obs_buf = self.observation_manager.compute()
+        self.obs_buf = self.observation_manager.compute(update_history=True)
 
         # return observations
         return self.obs_buf, self.extras
@@ -416,7 +416,7 @@ class ManagerBasedEnv:
             self.event_manager.apply(mode="interval", dt=self.step_dt)
 
         # -- compute observations
-        self.obs_buf = self.observation_manager.compute()
+        self.obs_buf = self.observation_manager.compute(update_history=True)
         self.recorder_manager.record_post_step()
 
         # return observations and extras

source/isaaclab/isaaclab/envs/manager_based_rl_env.py

@@ -237,7 +237,7 @@ class ManagerBasedRLEnv(ManagerBasedEnv, gym.Env):
             self.event_manager.apply(mode="interval", dt=self.step_dt)
         # -- compute observations
         # note: done after reset to get the correct observations for reset envs
-        self.obs_buf = self.observation_manager.compute()
+        self.obs_buf = self.observation_manager.compute(update_history=True)
 
         # return observations, rewards, resets and extras
         return self.obs_buf, self.reward_buf, self.reset_terminated, self.reset_time_outs, self.extras

source/isaaclab/isaaclab/managers/observation_manager.py

@@ -245,12 +245,17 @@ class ObservationManager(ManagerBase):
         # nothing to log here
         return {}
 
-    def compute(self) -> dict[str, torch.Tensor | dict[str, torch.Tensor]]:
+    def compute(self, update_history: bool = False) -> dict[str, torch.Tensor | dict[str, torch.Tensor]]:
         """Compute the observations per group for all groups.
 
         The method computes the observations for all the groups handled by the observation manager.
         Please check the :meth:`compute_group` on the processing of observations per group.
 
+        Args:
+            update_history: The boolean indicator without return obs should be appended to observation history.
+                Default to False, in which case calling compute_group does not modify history. This input is no-ops
+                if the group's history_length == 0.
+
         Returns:
             A dictionary with keys as the group names and values as the computed observations.
             The observations are either concatenated into a single tensor or returned as a dictionary
@@ -260,14 +265,14 @@ class ObservationManager(ManagerBase):
         obs_buffer = dict()
         # iterate over all the terms in each group
         for group_name in self._group_obs_term_names:
-            obs_buffer[group_name] = self.compute_group(group_name)
+            obs_buffer[group_name] = self.compute_group(group_name, update_history=update_history)
         # otherwise return a dict with observations of all groups
 
         # Cache the observations.
         self._obs_buffer = obs_buffer
         return obs_buffer
 
-    def compute_group(self, group_name: str) -> torch.Tensor | dict[str, torch.Tensor]:
+    def compute_group(self, group_name: str, update_history: bool = False) -> torch.Tensor | dict[str, torch.Tensor]:
         """Computes the observations for a given group.
 
         The observations for a given group are computed by calling the registered functions for each
@@ -290,6 +295,9 @@ class ObservationManager(ManagerBase):
         Args:
             group_name: The name of the group for which to compute the observations. Defaults to None,
                 in which case observations for all the groups are computed and returned.
+            update_history: The boolean indicator without return obs should be appended to observation group's history.
+                Default to False, in which case calling compute_group does not modify history. This input is no-ops
+                if the group's history_length == 0.
 
         Returns:
             Depending on the group's configuration, the tensors for individual observation terms are
@@ -330,13 +338,23 @@ class ObservationManager(ManagerBase):
                 obs = obs.mul_(term_cfg.scale)
             # Update the history buffer if observation term has history enabled
             if term_cfg.history_length > 0:
-                self._group_obs_term_history_buffer[group_name][term_name].append(obs)
-                if term_cfg.flatten_history_dim:
-                    group_obs[term_name] = self._group_obs_term_history_buffer[group_name][term_name].buffer.reshape(
-                        self._env.num_envs, -1
+                circular_buffer = self._group_obs_term_history_buffer[group_name][term_name]
+                if update_history:
+                    circular_buffer.append(obs)
+                elif circular_buffer._buffer is None:
+                    # because circular buffer only exits after the simulation steps,
+                    # this guards history buffer from corruption by external calls before simulation start
+                    circular_buffer = CircularBuffer(
+                        max_len=circular_buffer.max_length,
+                        batch_size=circular_buffer.batch_size,
+                        device=circular_buffer.device,
                     )
+                    circular_buffer.append(obs)
+
+                if term_cfg.flatten_history_dim:
+                    group_obs[term_name] = circular_buffer.buffer.reshape(self._env.num_envs, -1)
                 else:
-                    group_obs[term_name] = self._group_obs_term_history_buffer[group_name][term_name].buffer
+                    group_obs[term_name] = circular_buffer.buffer
             else:
                 group_obs[term_name] = obs
 

source/isaaclab/test/envs/test_manager_based_env.py

@@ -23,6 +23,8 @@ import omni.usd
 import pytest
 
 from isaaclab.envs import ManagerBasedEnv, ManagerBasedEnvCfg
+from isaaclab.managers import ObservationGroupCfg as ObsGroup
+from isaaclab.managers import ObservationTermCfg as ObsTerm
 from isaaclab.scene import InteractiveSceneCfg
 from isaaclab.utils import configclass
 
@@ -34,6 +36,22 @@ class EmptyManagerCfg:
     pass
 
 
+@configclass
+class EmptyObservationWithHistoryCfg:
+    """Empty observation with history specifications for the environment."""
+
+    @configclass
+    class EmptyObservationGroupWithHistoryCfg(ObsGroup):
+        """Empty observation with history specifications for the environment."""
+
+        dummy_term: ObsTerm = ObsTerm(func=lambda env: torch.randn(env.num_envs, 1, device=env.device))
+
+        def __post_init__(self):
+            self.history_length = 5
+
+    empty_observation: EmptyObservationGroupWithHistoryCfg = EmptyObservationGroupWithHistoryCfg()
+
+
 @configclass
 class EmptySceneCfg(InteractiveSceneCfg):
     """Configuration for an empty scene."""
@@ -67,6 +85,32 @@ def get_empty_base_env_cfg(device: str = "cuda:0", num_envs: int = 1, env_spacin
     return EmptyEnvCfg()
 
 
+def get_empty_base_env_cfg_with_history(device: str = "cuda:0", num_envs: int = 1, env_spacing: float = 1.0):
+    """Generate base environment config based on device"""
+
+    @configclass
+    class EmptyEnvWithHistoryCfg(ManagerBasedEnvCfg):
+        """Configuration for the empty test environment."""
+
+        # Scene settings
+        scene: EmptySceneCfg = EmptySceneCfg(num_envs=num_envs, env_spacing=env_spacing)
+        # Basic settings
+        actions: EmptyManagerCfg = EmptyManagerCfg()
+        observations: EmptyObservationWithHistoryCfg = EmptyObservationWithHistoryCfg()
+
+        def __post_init__(self):
+            """Post initialization."""
+            # step settings
+            self.decimation = 4  # env step every 4 sim steps: 200Hz / 4 = 50Hz
+            # simulation settings
+            self.sim.dt = 0.005  # sim step every 5ms: 200Hz
+            self.sim.render_interval = self.decimation  # render every 4 sim steps
+            # pass device down from test
+            self.sim.device = device
+
+    return EmptyEnvWithHistoryCfg()
+
+
 @pytest.mark.parametrize("device", ["cuda:0", "cpu"])
 def test_initialization(device):
     """Test initialization of ManagerBasedEnv."""
@@ -90,3 +134,67 @@ def test_initialization(device):
         obs, ext = env.step(action=act)
     # close the environment
     env.close()
+
+
+@pytest.mark.parametrize("device", ["cuda:0", "cpu"])
+def test_observation_history_changes_only_after_step(device):
+    """Test observation history of ManagerBasedEnv.
+
+    The history buffer should only change after a step is taken.
+    """
+    # create a new stage
+    omni.usd.get_context().new_stage()
+    # create environment with history length of 5
+    env = ManagerBasedEnv(cfg=get_empty_base_env_cfg_with_history(device=device))
+
+    # check if history buffer is empty
+    for group_name in env.observation_manager._group_obs_term_names:
+        group_term_names = env.observation_manager._group_obs_term_names[group_name]
+        for term_name in group_term_names:
+            torch.testing.assert_close(
+                env.observation_manager._group_obs_term_history_buffer[group_name][term_name].current_length,
+                torch.zeros((env.num_envs,), device=device, dtype=torch.int64),
+            )
+
+    # check if history buffer is empty after compute
+    env.observation_manager.compute()
+    for group_name in env.observation_manager._group_obs_term_names:
+        group_term_names = env.observation_manager._group_obs_term_names[group_name]
+        for term_name in group_term_names:
+            torch.testing.assert_close(
+                env.observation_manager._group_obs_term_history_buffer[group_name][term_name].current_length,
+                torch.zeros((env.num_envs,), device=device, dtype=torch.int64),
+            )
+
+    # check if history buffer is not empty after step
+    act = torch.randn_like(env.action_manager.action)
+    env.step(act)
+    group_obs = dict()
+    for group_name in env.observation_manager._group_obs_term_names:
+        group_term_names = env.observation_manager._group_obs_term_names[group_name]
+        group_obs[group_name] = dict()
+        for term_name in group_term_names:
+            torch.testing.assert_close(
+                env.observation_manager._group_obs_term_history_buffer[group_name][term_name].current_length,
+                torch.ones((env.num_envs,), device=device, dtype=torch.int64),
+            )
+            group_obs[group_name][term_name] = env.observation_manager._group_obs_term_history_buffer[group_name][
+                term_name
+            ].buffer
+
+    # check if history buffer is not empty after compute and is the same as the buffer after step
+    env.observation_manager.compute()
+    for group_name in env.observation_manager._group_obs_term_names:
+        group_term_names = env.observation_manager._group_obs_term_names[group_name]
+        for term_name in group_term_names:
+            torch.testing.assert_close(
+                env.observation_manager._group_obs_term_history_buffer[group_name][term_name].current_length,
+                torch.ones((env.num_envs,), device=device, dtype=torch.int64),
+            )
+            assert torch.allclose(
+                group_obs[group_name][term_name],
+                env.observation_manager._group_obs_term_history_buffer[group_name][term_name].buffer,
+            )
+
+    # close the environment
+    env.close()