DaveRc/ghosttrial-g1-scorpion

GhostTrial — Scorpion spear throw into an uppercut, on a Unitree G1

A fine-tune of NVIDIA's SONIC whole-body controller that performs a two-part combat phrase the stock controller cannot: a spear throw, a pull back, and a crouch into a rising uppercut, as one continuous motion under full physics.

Entered in Ghost Trial 03 (Ultimate Bots hackathon, Martial Arts track). Code, data and the full pipeline: https://github.com/SpiRaiL/GhostTrial-public

Files

file	what it is
model_step_003750_g1.onnx	the encoder trained on G1-space motion — the one this pipeline drives
model_step_003750_encoder.onnx	motion encoder
model_step_003750_decoder.onnx	policy decoder
config.yaml	the training run exactly as it ran
model_config.yaml	model dimensions, written by the exporter

How it was trained

Fine-tuned from the SONIC release checkpoint — not trained from scratch — on one motion: our own capture, retargeted to the G1 and rebuilt twelve times.

Base	SONIC release checkpoint (GR00T-WholeBodyControl)
Environments	4096 parallel, Isaac Lab 2.3.2, one H100 on Nebius
Checkpoint	step 3750
Actor / critic LR	2e-5 / 1e-3, gamma 0.99, seed 0
Motion	data/motion_lib_capture/robot/t12 in the GitHub repo
Export	tools/export_onnx.sh <checkpoint> /gt/data/motion_lib_capture/robot/t12

Data

A movement phrase written as a brief and filmed by a commissioned performer, lifted to 3D pose from monocular video, retargeted to the G1's 29 DoF, then corrected across eleven revisions for self-collision, foot contact and joint limits before any GPU time was spent. The motion data is in the GitHub repo; the performer's video is not published.

The 1992 Mortal Kombat behind-the-scenes footage that inspired the move is style reference only. It never entered training and is not distributed.

Before and after

Same reference motion, stock SONIC against this fine-tune, both under full physics in Isaac Lab:

	stock	this model
Pelvis height range over the phrase	74.3–78.7 cm (4 cm)	46.3–79.3 cm (33 cm)
The crouch the move is built on	never happens	performed
Drift from start over 14 s	0 cm	4 cm

The stock controller stays upright and marks time. This one drives into the stance, drops into the crouch and carries the arm through.

Limitations

• It holds 97% double support where the target asks for 58%: it plants where the reference leaves the floor, so the airborne part of the uppercut is damped.
• Trained on one phrase with standing, idle and walking control takes alongside it. Walking and turning were not separately evaluated against this checkpoint.
• Simulation only. It has never run on a physical G1.

Licence

Derived from SONIC model weights, which are under the NVIDIA Open Model License — that licence governs this derivative too. The pipeline code in the GitHub repo is ours.