iGPC: Generative Motion Priors for Object-Aware Humanoid Interaction
Authors: Anujith Muraleedharan, Abdul Ahad Butt, Nolan Fey, Yash Prabhu, Anamika J H, Sandor Felber, Maurice Rahme, Ivan Laptev
Organizations: Mohamed bin Zayed University of Artificial Intelligence (MBZUAI), Abu Dhabi, United Arab Emirates. · Massachusetts Institute of Technology (MIT), Cambridge, MA, USA. · Minerva Humanoids, Inc.
Humanoid robots operating in unstructured environments must combine robust whole-body control with the ability to perceive and physically interact with surrounding objects. While large-scale human motion data provides powerful priors for natural and versatile humanoid control, effectively transferring such priors to perception-driven object interaction remains challenging. To address this bottleneck, we propose a framework that extends the recently proposed Generative Pretrained Controller (GPC) from general human motion to full-body humanoid-environment interaction. First, we adapt GPC into interaction experts conditioned on scene affordance cues and privileged state information. These experts leverage the pretrained human motion prior while learning task-specific contact behaviors, including reaching toward objects, grasping environmental supports for stabilization, and pushing movable objects. Second, we introduce a perception-driven student that retains the pretrained GPC policy and distills interaction skills from the experts using onboard sensory observations. To bridge the gap between privileged expert observations and sensory inputs, we propose two complementary training objectives that enable effective adaptation of the pretrained motion prior during distillation. Notably, our experiments across multiple whole-body interaction tasks demonstrate that large-scale generative human motion priors provide an effective foundation for learning deployable policies for humanoid interactions in contact-rich real-world environments.
Figures & tables
Fig. 1: iGPC adapts human-motion priors to perceptive whole-body interaction on Unitree G1. Real-world sequences illustrate rail-assisted stabilization following an external push (top) and box pushing (bottom).
Method
Object manipulation
Reactive hand- supported stabilization
Onboard- perceptive contact
Motion- reference- free execution
Frozen- backbone low-rank adaptation
GPC [ 5 ]
–
–
–
✓
✓
BeyondMimic [ 2 ]
–
–
–
✓
–
ResMimic [ 8 ]
✓
–
–
–
–
ULTRA [ 10 ]
✓
–
✓
✓
–
LessMimic [ 11 ]
✓
–
✓
✓
–
ViBe [ 12 ]
✓
–
✓
∘v
✓
TABLE I: Qualitative comparison of selected methods.
Fig. 2: Overview of the proposed generative control framework. (A) Expert learning. A G1-specific motion controller and autoregressive motor prior form the motor foundation. Motion–scene supervision initializes object-conditioned task adapters, which are subsequently refined using privileged simulation observations. (B) Student learning. Depth, LiDAR, and proprioceptive history reconstruct the expert’s observation interface. Observation, token, and action supervision train the estimator, followed by bounded input calibration and task-adapter refinement. Calibrated observations o~t condition token selection, while the physical-state estimate s^t bypasses this correction and directly conditions the decoder Dψ . Flames indicate modules trained in the corresponding step; snowflakes indicate frozen learned modules. Dashed orange arrows indicate training supervision.
Fig. 3: Qualitative comparison of commanded rail-contact acquisition. Snapshots at t=2.56s compare the policies evaluated in Table II : MaskedMimic hand targeted to rail (top left), GPC (top right), GPC w/o support observation (bottom left), iGPC (ours, bottom right).
Policy
Interaction pre-training
Affordance pre-training
Crown contact (%) ↑
Endpoint error p50/p90 (cm) ↓
Time to crown p50/p90 (s) ↓
MaskedMimic (Hand Target)
—
—
0.20
12.07/15.55
1.45/2.75
GPC (w/o Interaction)
×
×
31.30
16.03/36.43
4.90/9.00
GPC (w/o Affordance)
✓
×
48.63
15.03/32.88
3.93/8.44
iGPC (ours)
✓
✓
99.32
1.35/11.04
0.76/1.46
TABLE II: Expert policy evaluation for commanded rail-contact task.
Policy
Obs. loss
Token loss
Crown contact (%) ↑
Body collision (%) ↓
Endpoint error p50/p90 (cm) ↓
Teacher-target MAE (rad) ↓
Expert iGPC
—
—
99.32
15.19
1.35/11.04
—
Student MLP
—
—
46.53
50.73
11.19/86.78
0.178396
iGPC (no obs. or token)
×
×
25.39
17.19
51.78/146.20
0.127518
iGPC (no obs.)
×
✓
93.41
13.13
1.37/8.38
0.088503
iGPC (no token)
✓
×
90.14
10.55
2.68/16.22
0.088679
iGPC (no prior calibration)
✓
✓
91.02
10.79
1.62/13.53
0.085493
TABLE III: Perception-based student policy evaluation for commanded rail-contact task.
Fig. 4: Reactive stabilization in simulation. Top: leg-only GPC. Bottom: iGPC student with sensor visualizations. The red arrow indicates the applied disturbance.
(a) Reactive stabilization : physical falls ↓
Push Δv (m/s)
iGPC expert
iGPC student
GPC leg-only
1.5–2.0
3 (0.59%)
5 (0.98%)
12 (2.34%)
2.0–2.5
24 (4.69%)
25 (4.88%)
94 (18.36%)
2.5–3.0
116 (22.66%)
88 (17.19%)
207 (40.43%)
(b) Box pushing
Metric
iGPC expert
iGPC student
VisualMimic
TABLE IV: Whole-body interaction. (a) Physical falls, count (%), on 512 trials per push band. (b) Forward displacement and absolute lateral drift at first fall or 60 s: mean ± SD across four evaluation-seed means (128 trials each).
The Hong Kong University of Science and Technology (Guangzhou) · Artificial General Intelligence Institute, University of Science and Technology of China · The University of Hong Kong +1