dim-go2-sim

A simulated Unitree Go2 for dimOS, as one module: cmd_vel in; a rolling Livox Mid-360, a textured front camera, IMU, odometry, tf and contacts out. It drops into a blueprint where a real Go2 would be.

pip install dim-go2-sim

from dimos.core.coordination.blueprints import autoconnect
from dim_go2_sim import Go2Sim

blueprint = autoconnect(
    Go2Sim.blueprint(scene={"package": "supermarket", "start": (18.5, 10.0, -0.17)}),
    MyNavigation.blueprint(),  # anything that reads lidar/odom and writes cmd_vel
)

With no scene it stands on bare ground. A scene is either a cooked dimOS scene package by name (scene.package), or an MJCF of the collision geometry (scene.mjcf) and optionally a textured glTF the camera draws (scene.visual).

Streams

Config

Go2SimConfig has a section per part, each overridable from a blueprint or the dimOS CLI:

• scene: package, mjcf, visual, visual_y_up, start (x, y, yaw), floor_z, floor_top_z
• physics: timestep, fitted, actuator_tau, policy, track_velocity, command_timeout, max_velocity, realtime, cache_dir
• lidar: enabled, rate_hz, xyz, pitch_deg, point_rate_hz, downsample, min_range, max_range, noise, dropout, self_occlusion, motion_bins_hz, seed
• camera: enabled, rate_hz, width, height, fovy_deg, xyz, pitch_deg, near, far, detail_distance, simplify, ambient, sun, background
• odom_hz, imu_hz, frame_prefix

See src/dim_go2_sim/config.py for what each means and its default.

How it works

• Walking. MuJoCo steps the Go2 under the open rl_sar robot_lab policy at 50 Hz, with joint damping, friction, armature, masses, foot friction and a 15 ms motor lag fitted to real Go2 runs under that policy. The policy alone ignores slow commands and drifts when told to stand, so an integral loop on the true body velocity trims its command, as the Go2's sport mode tracks it (physics.track_velocity).
• Lidar. The Mid-360's four-channel Fourier firing pattern, 200k points a second, cast in 5 ms slices from wherever the head is then, with range noise and grazing-angle dropout. The static scene is cast through Embree; the robot's own body, through MuJoCo. A cooked store of 48k geoms scans at the full 10 Hz.
• Camera. pygfx draws the scene's textured glTF in a child process, its meshes merged by material and 4 m cell (a 47k-node store: 0.6 → 60+ fps on an M-series Mac, every object drawn). It draws the scene only, not the robot. On a software GPU (Mesa's lavapipe, e.g. in Docker: install mesa-vulkan-drivers) it simplifies the scene and draws small objects only within 4 m, to keep a store at several frames a second (camera.simplify, camera.detail_distance).
• The composed world is compiled once and cached (physics.cache_dir, default ~/.cache/dim_go2_sim); a store takes about 2 minutes the first time.

Development

uv venv --python 3.12 && uv pip install -e . pytest
pytest

Licenses

Apache-2.0. Bundled data keeps its own terms: the Go2 model (Unitree, BSD-3, data/go2/LICENSE), the walking policy (rl_sar, Apache-2.0, data/policy/NOTICE), and the Mid-360 pattern (data/mid360/NOTICE.md).