EgoDelta: From Egocentric Scene Change to 3D Attachment Targets for Agricultural Manipulation

Nam Ho Koh1,* Junyoung Jang2,* Chaeyoung Oh1 Changwoo Yoo1 Jongho Lee3 Kee-Eung Kim1

1Kim Jaechul Graduate School of AI, KAIST, Daejeon, Republic of Korea 2KT Corporation, Seoul, Republic of Korea 3Daedong AI Lab

*Equal contribution

WACV 2027 · Applications Track

EgoDelta turns the scene change left behind by a human removal demonstration into 3D attachment targets and robot-ready trajectories for harvesting and deleafing.

EgoDelta in four panels: an egocentric pre- and post-action demonstration recorded with Aria glasses, pre- and post-action 2DGS reconstructions for deleafing and harvesting, removal-score maps with the extracted attachment target, and a robot executing the generated trajectory on a tomato-vine rig.
Overview of EgoDelta. From an egocentric removal demonstration, EgoDelta reconstructs the pre- and post-action scene states with 2DGS, localizes the removed component, and recovers its 3D attachment target. It combines the recovered target with demonstrated motion to generate robot-specific trajectories for learning and execution.

Abstract

Agricultural tasks such as fruit harvesting and deleafing require removing components at their attachment targets: the 3D locations where they connect to the plant. These targets are often occluded and need not coincide with component centers. Egocentric video captures human removal demonstrations without requiring robot hardware, but provides neither 3D target labels nor robot-executable motion. The persistent scene change produced by a completed removal nevertheless provides spatial evidence of both the removed component and its former connection. We introduce EgoDelta, an integrated pipeline that recovers attachment targets from this evidence without attachment-target annotations and converts the demonstrations into robot-specific supervision. EgoDelta reconstructs the pre- and post-action scene states with 2D Gaussian Splatting and scores each pre-action surface using geometric and appearance changes weighted by observation reliability. It uses these scores to localize the removed component and retains them together with evidence from nearby remaining plant surfaces to recover the former connection. Recovered targets supervise an attachment-target predictor, while target-anchored robot-specific trajectories adapted from tracked hand motion supervise a target-conditioned policy. Across 160 targets from 60 interventions, EgoDelta achieves 92.83% F1 at a 3 cm matching tolerance. Across 180 physical robot trials, executing EgoDelta-generated trajectories without policy learning succeeds in 100% of trials, compared with 43.3% for direct human-motion retargeting. The learned policy succeeds in 91.7% of trials.

Quantitative results

Headline numbers from the paper's main tables: 30 tomato-vine scenes, 60 harvesting and deleafing interventions, 160 attachment targets and 180 physical robot trials. Hover a bar for the per-setting breakdown.

Removed-component localization
overall F1 (%) ↑ · 720 reference masks
0 25 50 75 100 48.0 MV3DCD 55.4 Point-cloud residual 79.5 EgoDelta (ours)
3D attachment-target recovery
overall F1@3 cm (%) ↑ · 160 targets
0 25 50 75 100 26.3 Point-cloud residual 28.7 EgoDelta binary input 92.8 EgoDelta (ours)
Physical robot execution
success rate (%) ↑ · 60 trials per mode
0 25 50 75 100 43.3 Human-motion retargeting 91.7 EgoDelta learned policy 100.0 EgoDelta trajectories
Table 1 · 2D removed-component localization
HarvestingDeleafingOverall
Method IoU (%) ↑ F1 (%) ↑ IoU (%) ↑ F1 (%) ↑ IoU (%) ↑ F1 (%) ↑
Point-cloud residual 29.643.151.367.640.455.4
YOLOE-Seg 26.240.96.111.016.126.0
SAM 3 28.843.730.346.029.644.8
3DGS-CD 27.132.04.98.216.020.1
GS-DIFF 11.219.734.050.222.635.0
MV3DCD 33.145.536.750.634.948.0
EgoDelta (ours) 62.475.871.583.267.079.5

All methods are evaluated against the same 720 reference masks; the point-cloud residual receives only MPS semi-dense point clouds. Best results per column are in bold.

Show Tables 2–5 from the paper
Table 2 · Ablation of removed-component localization
HarvestingDeleafingOverall
Method IoU (%) ↑ F1 (%) ↑ IoU (%) ↑ F1 (%) ↑ IoU (%) ↑ F1 (%) ↑
Appearance only 60.071.968.881.264.476.6
Geometry only 49.359.871.282.960.271.4
No observability weight 49.664.670.782.660.273.6
No shared-view filter 62.675.970.782.766.779.2
Fixed-radius match 52.263.070.982.861.572.9
EgoDelta (full) 62.475.871.583.267.079.5

Each variant changes one scene-comparison choice; all values are percentages under the 720-mask protocol of Table 1. Best results per column are in bold.

How EgoDelta works

A completed removal leaves a persistent change in the scene. EgoDelta compares 3D reconstructions from before and after the action to find what was removed and where it was attached, then turns that target into robot supervision. No attachment-target annotations are needed.

  1. 01

    Egocentric pre/post demonstration

    A worker wearing Project Aria glasses records one continuous removal. Aria MPS provides camera poses and semi-dense scene points; frames sampled before and after the action form two view sets that need not share viewpoints.

  2. 02

    2DGS reconstruction

    The plant is reconstructed independently before and after removal with 2D Gaussian Splatting in a common scene frame, so geometry removed by the action is absent from the post-action model.

  3. 03

    Extract attachment target

    Each pre-action surface primitive is scored by its geometric and appearance mismatch, weighted by how reliably it was observed. Continuous scores and remaining-surface evidence then locate the former connection.

  4. 04

    Robot trajectory generation

    The target anchors the robot's contact point while tracked hand motion supplies approach and manipulation directions, yielding feasible trajectories that also supervise a target-conditioned policy.

Training diagram: recovered attachment targets for deleafing and harvesting supervise an attachment-target predictor, an object detector with a target head that outputs projected 2D target heatmaps, while generated robot trajectories supervise a target-conditioned policy through behavior cloning with an L2 loss.
Attachment-target-conditioned training. Recovered targets supervise the image-space attachment-target predictor and condition policy learning; robot-specific trajectories provide behavior-cloning supervision. At deployment, both use only the current robot RGB-D observation and state.

Removed-component localization

Qualitative comparison on one harvesting and one deleafing example, with the RGB overlay on top and the binary prediction below. Competing methods often respond to foliage or reconstruction artifacts, while EgoDelta keeps the thin extent of the removed component.

Grid comparing point-cloud residual, YOLOE-Seg, SAM 3, 3DGS-CD, GS-DIFF, MV3DCD, EgoDelta and the reference on a harvesting and a deleafing example. Baselines show many false-positive regions on foliage; EgoDelta's prediction closely follows the reference boundary.
Qualitative comparison of 2D removed-component localization. EgoDelta more consistently preserves the thin extent of removed components while suppressing responses to foliage and reconstruction artifacts.

From demonstration to robot motion

Each tab follows one demonstration recorded with Project Aria glasses. The middle panel illustrates what EgoDelta does with it: reconstruct both scene states, score the removed component, place the attachment target, and plan a robot trajectory that reaches it.

Egocentric demonstration
EgoDelta pipeline (illustration)
Robot execution

Robot execution

A fixed-base RB-Y1 with one 7-DoF arm and an interaction-specific end effector, tested on held-out arrangements disjoint from the perception benchmark. A trial succeeds only if the intended component is removed without contacting another target, damaging the plant, triggering a safety stop, or requiring intervention.

Deleafing and harvesting examples: egocentric demonstration frames with the target highlighted, next to the robot following the generated trajectory to the attachment target on the tomato-vine rig.
From recovered attachment targets to robot execution. The recovered target anchors robot contact, while demonstration-derived motion and the interaction and robot specifications instantiate a feasible robot-specific trajectory.

180 physical robot trials

  • success (EgoDelta)
  • success (baseline)
  • failure
Direct human-motion retargeting
Harvesting 12/30
Deleafing 14/30
EgoDelta trajectories (no policy learning)
Harvesting 30/30
Deleafing 30/30
EgoDelta learned policy
Harvesting 28/30
Deleafing 27/30

Learned policy on the robot

The target-conditioned policy acting from the robot's own RGB-D observations.

Harvesting

Trial 1
Trial 2

Citation

@inproceedings{egodelta2027,
  title     = {{EgoDelta}: From Egocentric Scene Change to 3D Attachment Targets for Agricultural Manipulation},
  author    = {Koh, Nam Ho and Jang, Junyoung and Oh, Chaeyoung and Yoo, Changwoo and Lee, Jongho and Kim, Kee-Eung},
  booktitle = {Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision (WACV)},
  year      = {2027}
}