LIT

Breaking the Vision–Action Shortcut: Latent Interface Training for Generalizable Robotics Foundation Models

Jianman Lin1,∗Shailesh Shailesh2,∗Zhongyi Luo3Jiafei Duan2,†

* Equal contribution   ·   † Corresponding author

1South China University of Technology 2National University of Singapore 3Nanyang Technological University
Learning actions that generalize beyond the training scene.

The idea

Focus on the goal.

Robots can learn visual shortcuts that fail when the scene changes. LIT routes vision through a compact, pose-supervised interface so actions stay grounded in the task. It improves generalization across four robot model architectures.

Why visual shortcuts fail

Lighting, backgrounds, and camera views can correlate with actions during training. LIT constrains visual conditioning while retaining the spatial information needed to act.

Visual shortcuts and LIT training paradigms
LIT separates learning to act from learning to use vision.

How it works

Two stages. One spatial goal.

01   Learn to act

Train the action expert with language, robot state, and a target end-effector pose—without images.

02   Connect vision

Route visual features through latent tokens supervised to predict the same target pose.

LIT: action learning followed by a pose-supervised visual interface
The backbone and action expert are retained. The interface changes.

Real-world Exp

New scenes. More successful actions.

One policy, three tasks, and changes in lighting, camera view, and distractors.

In-distribution
88.0%
74.7% baseline · +13.3 pp
New lighting
70.0%
53.3% baseline · +16.7 pp
New camera
46.7%
30.0% baseline · +16.7 pp
Distractors
63.3%
50.0% baseline · +13.3 pp

Selected rollouts: baseline failures (left), LIT successes (right). Rates above aggregate all trials. OOD = out of distribution; pp = percentage points.

Success rates by task
Success rates by task and visual condition
Three tasks on the YAM dual-arm platform. Camera OOD uses only the top camera.

Simulation results

Generalization across four architectures.

LIT improves average success on LIBERO-Plus while preserving or improving in-distribution performance.

π0.5
79.67%
68.97% baseline
MolmoAct2
71.92%
63.62% baseline
FAST-WAM
60.63%
51.44% baseline
ImageWAM
86.89%
83.02% baseline

LIBERO-Plus: mean success across seven perturbation categories.

Full LIBERO-Plus results
Perturbationπ0.5 (VLA)MolmoAct2 (VLA)FAST-WAM (WAM)ImageWAM (WAM)
BaseLITΔBaseLITΔBaseLITΔBaseLITΔ
Camera Viewpoints58.2980.30+22.0139.4048.41+9.0116.4043.83+27.4382.1684.55+2.39
Sensor Noise79.8991.94+12.0549.0370.77+21.7437.7056.89+19.1996.5497.57+1.03
Lighting Conditions82.4090.11+7.7184.8685.64+0.7878.2083.89+5.6997.6597.99+0.34
Background Textures85.3286.99+1.6789.7894.42+4.6453.7057.22+3.5288.2694.24+5.98
Robot Initial States60.7163.71+3.0050.7159.03+8.3244.5048.86+4.3647.8160.19+12.38
Object Layout64.0073.11+9.1155.9071.61+15.7160.7064.17+3.4777.7283.67+5.95
Language Instructions52.1571.50+19.3575.6973.58−2.1168.9069.55+0.6590.9790.05−0.92
Overall68.9779.67+10.7063.6271.92+8.3051.4460.63+9.1983.0286.89+3.87

Success (%). Δ is the change from the paired baseline.

In-distribution LIBERO results
ModelVariantSpatialObjectGoalLongAvg.
π0.5 VLABaseline88.6093.4089.2079.8087.75
LIT90.2098.8093.4084.8091.80
MolmoAct2 VLABaseline93.0097.8095.4087.8093.50
LIT94.6096.2095.2090.4094.10
FAST-WAM WAMBaseline98.20100.0097.0095.2097.60
LIT98.8099.8098.4095.4098.10
ImageWAM WAMBaseline98.40100.0097.6096.4098.10
LIT99.6099.2099.2095.6098.40

Success (%). Better results within each architecture are bold.

Inside the interface

See the predicted goal.

Red marks the predicted target pose; cyan marks the current gripper pose. Predictions come from vision. MolmoAct2 rollouts play at half speed.

8 in-distribution rollouts
8 out-of-distribution rollouts

Unseen cameras, lighting, backgrounds, and distractors.

A closer look

What makes the difference?

Task-focused attention

LIT’s attention stays closer to relevant robot–object regions as scenes change.

Responsive to goals

Actions resist irrelevant visual changes and adapt when the goal changes.

Both stages matter

Removing the action prior or pose supervision reduces generalization.

Attention and intervention figures

Explore the attention

Drag either image. Both views move together.

Baseline
Clean scene, raw input
Clean scene, Baseline attention overlay
LIT
Clean scene, raw input
Clean scene, LIT attention overlay
50% attention
Trajectories under distractors, blur, and changed instructions
LIT resists irrelevant visual changes and responds to a new goal.
Training dynamics
Action and pose losses over training
Compared at the same 30K-step training budget, LIT reaches a lower action loss.
Ablation results
VariantIDOOD: LIBERO-Plus
LIBERO Avg.CameraNoiseLightingBackgr.RobotLayoutLang.Overall
MolmoAct293.5039.4049.0384.8689.7850.7155.9075.6963.62
Vanilla staged training93.7543.2852.0985.1788.0855.1660.9873.4665.46
LIT w/o Stage 1 & pose supervision93.4539.8449.3487.2289.6353.0068.2072.6765.70
LIT w/o Stage 193.7046.1554.6587.1386.3463.1066.4373.8068.23
LIT w/o pose supervision93.5042.7860.0291.0788.3857.8168.8573.1168.86
Baseline w/ pose supervision93.2040.3251.3089.0090.1355.4558.3773.5665.45
LIT w/ direct visual access94.2542.9655.2888.1889.2262.4963.7472.3367.74
LIT94.1048.4170.7785.6494.4259.0371.6173.5871.92

MolmoAct2 success (%). LIT reaches 71.92% on LIBERO-Plus; removing Stage 1 gives 68.23%, and removing pose supervision gives 68.86%.