[go: up one dir, main page]

Accepted at NeurIPS 2026

LessMimic Versatile Humanoid–Object Interaction with
Unified Distance Field Representations

Yutang Lin*, 1, 2, 3, 5, 7, 8 Jieming Cui*, 1, 2, 3, 5, 7, 8 Yixuan Li4, 2, 5
Wei Liang4 Baoxiong Jia†, 2, 5 Yixin Zhu†, 3, 1, 5, 6, 7, 8 Siyuan Huang†, 2, 5
*Equal contribution   †Corresponding author
1Institute for AI, Peking University
2Beijing Institute for General Artificial Intelligence (BIGAI)
3School of Psychological and Cognitive Sciences, Peking University
4School of Computer Science and Technology, Beijing Institute of Technology
5State Key Lab of General AI
6XS Vision
7Beijing Key Laboratory of Behavior and Mental Health, Peking University
8Embodied Intelligence Lab, PKU-Wuhan Institute for Artificial Intelligence

Key Contributions #

Generalize across objects

The same policy lifts and manipulates objects with diverse geometry (e.g., 23 cm box to 60 cm cylinder) by operating on a distance-field representation.

How we achieve this

We represent interaction in a distance-field space, which acts like a quotiented task space over object geometry. This gives the policy dense local geometric cues that transfer across object shape and scale without redesigning task formulations.

Multiple skills in one policy

A single policy composes pick up, push, sit/stand, and carry over long horizons without task-specific modules.

How we achieve this

We build a unified interaction representation shared by all skills. With one common observation/reward interface across interactions, a single policy can learn skill composition from consistent inputs rather than isolated per-task pipelines.

No hand-crafted reward

Training uses adversarial interaction priors in the geometric domain instead of motion-tracking or hand-designed shaping rewards.

How we achieve this

We use discriminative objectives to enforce natural and physically reasonable interaction trajectories. This removes the need for brittle task-specific reward shaping and improves behavior quality across diverse interaction modes.

Root command & action label only

At inference, control is specified solely by target root trajectory and action labels; no motion exemplars or retargeting.

Why this matters

We simplify control inputs to root commands plus action labels, making human-in-the-loop control straightforward and enabling clean integration with upstream planners or VLM-driven instruction modules.

How We Do It

We use a distance-field-centric policy representation. The top row visualizes DF-driven interaction for three different skills (pick, push, sit), and the second row shows scale generalization.

LessMimic method overview converted from model PDF

Method Overview

Unified distance-field representation and policy learning pipeline.

DF Visualization: Pick
DF visualization for the pick skill
DF Visualization: Push
DF visualization for the push skill
DF Visualization: Sit
DF visualization for the sit skill
Scale Generalization in Simulation
Pick objects at different scales with distance-field visualization

Live MuJoCo Session

Use this embedded session to inspect online rollout behavior directly in-browser. Add your own objects to the session and interact with them.
Feel free to test how purely data-driven interaction policy complete tasks (or fail).

The live simulator is paused by default to avoid heavy startup on page load.

Hosted locally for reproducible demos and GitHub Pages compatibility. Open it in a new tab if you need more space: Humanoid Policy Viewer.
Note: The objects' DF is discretized and cached, so the policy's performance is slightly degraded. To report issues, please contact yutang.lin@stu.pku.edu.cn.
Please use Google Chrome for best performance.

1. Interact with Various Objects #

One policy generalizes across object shapes and sizes—box, foam cylinder, and ball.
*The foam cylinder and soccer ball are not in training data.

Pick up: box

2. Autonomously Recover from Disturbance/Failure #

After external disturbance or failed pickup attempts, the policy re-initiates interaction and recovers autonomously using continuous geometric feedback.

Recovery: box after slipperiness

3. Execute Consequent Long-Horizon Tasks #

A single policy composes multiple skills in sequence over extended horizons, showing smooth transitions between interaction modes.

Combination: sit → push (2x speed)

4. Mocap and Depth Input as Perception #

Our method runs with either motion-capture object state or egocentric depth only—enabling deployment with or without external tracking.

Mocap
Egocentric depth

Same task: left = mocap object state, right = depth-only policy.

Additional Vision-Only Demos

Push chest + chair (vision 2x speed)
Push chair (vision)

Our method can push objects with different geometries and scales. Thanks Yixuan for his dedication 😁.

Push + pick (vision 2x speed)
Push + pick (ego depth 2x speed)

Long-horizon completion: push + pick (vision). Right: egocentric depth perception.

Angle 1
Angle 2
Angle 3
Foam pickup from three different angles.

Quantitative Results at a Glance #

Visual summaries: simulation scale generalization, long-horizon completion, and real-world deployment.

Single-Task Scale Generalization (Ours)

One merged figure for PickUp success across object scales (from TABLE II).

63 64 0 0 23 0 100 95 100 18 71 0 100 91 100 100 100 100 88 100 41 100 48 0 94 93 2 63 40 0 0.4 (OOD) 0.6 1 1.4 1.6 (OOD)
Ours (Mocap) Ours (Vision) HDMI ResMimic PhysHSI VisualMimic
Y-axis is PickUp success (%) from 0 to 100. Ours variants remain strong at large scales while reference-based methods degrade sharply off reference scale.

Long-Horizon: Ours (Mocap) Only

Completion rate of our main method as the number of sequential tasks increases.

5 10 15 25 40 61.8 38.1 23.5 8.9 2.1
Task count grows from 5 to 40 without resets, showing graceful performance decay under much longer horizons.

Abstract #

Versatile whole-body interaction between humanoid robots and everyday objects is a central goal of embodied intelligence. Existing methods often rely on motion-reference inputs or task-specific rewards, which couple each policy to particular motion scripts, object geometries, and contact timings. This coupling limits both geometric generalization and flexible interaction control, in which simple commands specify the motion intent and the object geometry determines how contact is executed. Here we present LessMimic, a framework for versatile humanoid–object interaction that requires no motion reference at inference. A single whole-body policy is steered by root-velocity commands and an interaction-type flag, and it is conditioned on a compact interaction representation built from short histories of surface distances and local surface directions queried from a Distance Field (DF). This geometry-conditioned interface lets the commands set the motion intent while contact behavior adapts to the local object geometry. Visual distillation further transfers the interface to egocentric depth, which yields a variant that deploys without Motion Capture (MoCap). Across object scales from 0.4× to 1.6×, LessMimic performs robustly on four interaction tasks (PickUp, SitStand, Push, and Carry), whereas motion-conditioned baselines degrade sharply away from the training scale. The same policy also composes heterogeneous skills in sequence, succeeding on 62.1% of five-task sequences and on 23.5% of sequences with 15 task instances. Grounding interaction control in local geometry rather than in motion references thus offers a path toward humanoid–object control that generalizes across geometries, follows simple commands, and composes heterogeneous skills.

Paper (PDF)

If the PDF does not display, download it directly.

BibTeX

@inproceedings{lin2026lessmimic,
  title={LessMimic: Versatile Humanoid–Object Interaction with Unified Distance Field Representations},
  author={Lin, Yutang and Cui, Jieming and Li, Yixuan and Liang, Wei and Jia, Baoxiong and Zhu, Yixin and Huang, Siyuan},
  booktitle={Advances in Neural Information Processing Systems},
  year={2026}
}