Changelog

Changelog#

Upcoming version (not yet released)#

Breaking API changes

  • randomize_field no longer exists. Replace calls with typed functions from the new dr module (e.g. dr.geom_friction, dr.body_mass).

  • EventTermCfg no longer accepts domain_randomization. The @requires_model_fields decorator on each dr function takes care of field expansion automatically.

Added#

  • Cloud training support via SkyPilot and Lambda Cloud, with documentation covering setup, monitoring, and cost management.

  • W&B hyperparameter sweep scripts that distribute one agent per GPU across a multi-GPU instance.

  • Contributing guide with documentation for shared Claude Code commands (/update-mjwarp, /commit-push-pr).

  • Added optional ViewerConfig.fovy and apply it in native viewer camera setup when provided.

  • New dr module (mjlab.envs.mdp.dr) replacing randomize_field with typed per-field domain randomization functions. Each function automatically recomputes derived fields via set_const. Highlights:

    • Camera and light randomization: dr.cam_fovy, dr.cam_pos, dr.cam_quat, dr.cam_intrinsic, dr.light_pos, dr.light_dir. Camera and light names are now supported in SceneEntityCfg (camera_names / light_names).

    • dr.pseudo_inertia for physics-consistent randomization of body_mass, body_ipos, body_inertia, and body_iquat via the pseudo-inertia matrix parameterization (Rucker & Wensing 2022). Replaces the removed dr.body_inertia / dr.body_iquat.

    • dr.geom_size with automatic recomputation of geom_rbound and geom_aabb for broadphase consistency.

    • dr.tendon_armature and dr.tendon_frictionloss.

    • dr.body_quat, dr.geom_quat, and dr.site_quat with RPY perturbation composed onto the default quaternion.

    • Extensible Operation and Distribution types. Users can define custom operations and distributions as class instances and pass them anywhere a string is accepted. Built-in instances (dr.abs, dr.scale, dr.add, dr.uniform, dr.log_uniform, dr.gaussian) are exported from the dr module.

    • dr.mat_rgba for per-world material color randomization. Tints the texture color, useful for randomizing appearance of textured surfaces. Material names are now supported in SceneEntityCfg (material_names).

    • Fixed dr.effort_limits drifting on repeated randomization.

    • Fixed dr.body_com_offset not triggering set_const.

  • yam_lift_cube_vision_env_cfg now randomizes cube color (dr.geom_rgba) on every reset when cam_type="rgb".

  • The native viewer now reflects per-world DR changes to visual model fields on each reset. Geom appearance, body and site poses, camera parameters, and light positions are all synced from the GPU model before rendering. Inertia boxes (press I) and camera frustums (press Q) update correctly when the corresponding fields are randomized. See Domain Randomization for viewer-specific caveats.

  • MaterialCfg.geom_names_expr for assigning materials to geoms by name pattern during edit_spec.

  • TerrainEntityCfg now exposes textures, materials, and lights as configurable fields (previously hardcoded). Set textures=(), materials=() to use flat dr.geom_rgba instead of the default checker texture.

  • DebugVisualizer now supports ellipsoid visualization via add_ellipsoid.

  • Viewer single-step mode: press RIGHT arrow (native) or click “Step” (Viser) to advance exactly one physics step while paused.

  • Viewer error recovery: exceptions during stepping now pause the viewer and log the traceback instead of crashing the process.

  • Native viewer runs forward kinematics while paused, keeping perturbation visuals accurate.

  • Viewer speed multipliers use clean power-of-2 fractions (1/32x to 1x).

  • Visualizers display the realtime factor alongside FPS.

  • joint_torques_l2 now respects SceneEntityCfg.actuator_ids, allowing penalization of a subset of actuators instead of all of them (#703). Contribution by @saikishor.

  • Terrain is now a proper Entity subclass (TerrainEntity). This allows domain randomization functions to target terrain parameters (friction, cameras, lights) via SceneEntityCfg("terrain", ...). TerrainImporter / TerrainImporterCfg remain as aliases but will be deprecated in a future version.

  • Added upload_model option to RslRlBaseRunnerCfg to control W&B model file uploads (.pt and .onnx) while keeping metric logging enabled (#654).

Changed#

  • Self collision and illegal contact sensors now use history_length to catch contacts across decimation substeps. Reward and termination functions read force_history with a configurable force_threshold.

  • Replaced the single scale parameter in DifferentialIKActionCfg with separate delta_pos_scale and delta_ori_scale for independent scaling of position and orientation components.

  • Improved offscreen multi environment framing by selecting neighboring environments around the focused env instead of first N envs.

  • Tuned tracking task viewer defaults for tighter camera framing.

  • Disabled shadow casting on the G1 tracking light to avoid duplicate stacked shadows when robots are close.

Fixed#

  • Fixed viewer physics loop starving the renderer by replacing the single sim-time budget with a two-clock design (tracked vs actual sim time). Physics now self-corrects after overshooting, keeping FPS smooth at all speed multipliers.

  • Bundled ffmpeg for mediapy via imageio-ffmpeg, removing the requirement for a system ffmpeg install. Thanks to @rdeits-bd for the suggestion.

  • Fixed height_scan returning ~0 for missed rays; now defaults to max_distance. Replaced clip=(-1, 1) with scale normalization in the velocity task config. Thanks to @eufrizz for reporting and the initial fix (#642).

  • Fixed ghost mesh visualization for fixed-base entities by extending DebugVisualizer.add_ghost_mesh to optionally accept mocap_pos and mocap_quat (#645).

  • Fixed viser viewer crashing on scenes with no mocap bodies by adding an nmocap guard, matching the native viewer behavior.

  • Fixed offscreen rendering artifacts in large vectorized scenes by applying a render local extent override in OffscreenRenderer and restoring the original extent on close.

  • Fixed RslRlVecEnvWrapper.unwrapped to return the base environment, ensuring checkpoint state restore and logging work correctly when wrappers such as VideoRecorder are enabled.

Version 1.1.1 (February 14, 2026)#

Added#

  • Added reward term visualization to the native viewer (toggle with P) (#629).

  • Added DifferentialIKAction for task-space control via damped least-squares IK. Supports weighted position/orientation tracking, soft joint-limit avoidance, and null-space posture regularization. Includes an interactive viser demo (scripts/demos/differential_ik.py) (#632).

Fixed#

  • Fixed play.py defaulting to the base rsl-rl OnPolicyRunner instead of MjlabOnPolicyRunner, which caused a TypeError from an unexpected cnn_cfg keyword argument (#626). Contribution by @griffinaddison.

Changed#

  • Removed body_mass, body_inertia, body_pos, and body_quat from FIELD_SPECS in domain randomization. These fields have derived quantities that require set_const to recompute; without that call, randomizing them silently breaks physics (#631).

  • Replaced moviepy with mediapy for video recording. mediapy handles cloud storage paths (GCS, S3) natively (#637).

../_images/native_reward.png

Version 1.1.0 (February 12, 2026)#

Added#

  • Added RGB and depth camera sensors and BVH-accelerated raycasting (#597).

  • Added MetricsManager for logging custom metrics during training (#596).

  • Added terrain visualizer (#609). Contribution by @mktk1117.

../_images/terrain_visualizer.jpg

  • Added many new terrains including HfDiscreteObstaclesTerrainCfg, HfPerlinNoiseTerrainCfg, BoxSteppingStonesTerrainCfg, BoxNarrowBeamsTerrainCfg, BoxRandomStairsTerrainCfg, and more. Added flat patch sampling for heightfield terrains (#542, #581).

  • Added site group visualization to the Viser viewer (Geoms and Sites tabs unified into a single Groups tab) (#551).

  • Added env_ids parameter to Entity.write_ctrl_to_sim (#567).

Changed#

  • Upgraded rsl-rl-lib to 4.0.0 and replaced the custom ONNX exporter with rsl-rl’s built-in as_onnx() (#589, #595).

  • sim.forward() is now called unconditionally after the decimation loop. See When do I need to call sim.forward()? for details (#591).

  • Unnamed freejoints are now automatically named to prevent KeyError during entity init (#545).

Fixed#

  • Fixed randomize_pd_gains crash with num_envs > 1 (#564).

  • Fixed ctrl_ids index error with multiple actuated entities (#573). Reported by @bwrooney82.

  • Fixed Viser viewer rendering textured robots as gray (#544).

  • Fixed Viser plane rendering ignoring MuJoCo size parameter (#540).

  • Fixed HfDiscreteObstaclesTerrainCfg spawn height (#552).

  • Fixed RaycastSensor visualization ignoring the all-envs toggle (#607). Contribution by @oxkitsune.

Version 1.0.0 (January 28, 2026)#

Initial release of mjlab.

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