Krishi Attri

Robotics and AI researcher. M.S. SNU, incoming Ph.D. UCF.

I give robots a sense of touch.

Perception systems that see, feel, and reconstruct the world in real time: visuo-tactile SLAM on 3D Gaussian Splatting maps, plus the open-source tools that make the stack verifiable and fast.

GaussianFeels: 1.13 mm object tracking during in-hand manipulation, at 7.0–12.4× the frame rate of the neural-field baseline (simulation). splatreg, mathlas, HiCache++, CERT-FLOW on PyPI.

  • M.S. Mechanical Engineering · Seoul National University
  • Soft Robotics & Bionics Laboratory · Advisor: Prof. Yong-Lae Park
  • Incoming Ph.D. · University of Central Florida · ORCGS Doctoral Fellow · Aug 2026
Krishi Attri
Krishi Attri · Seoul, 2025
01Research

Perception through occlusion.

SLAM when the easy signal is denied: visuo-tactile perception through the robot's own grasp (M.S. thesis), dense visual SLAM, and GNSS-denied navigation (B.S. thesis research).

Live: the Gaussian map forming during in-hand manipulation. Raw camera input · the reconstruction forming · the accumulated map orbiting, tactile contacts in magenta.

GaussianFeels

Object-centric Gaussian SLAM for visuo-tactile in-hand manipulation

Thesis · release upcomingDec 2024 – Present

M.S. Thesis · Soft Robotics & Bionics Lab, Seoul National University

When a robot hand grasps an object, it occludes exactly the region it most needs to perceive. GaussianFeels fuses RGB-D vision, DIGIT tactile contact geometry, and hand proprioception into one explicit object-centric 3D Gaussian Splatting map, reconstructing and tracking objects online, through the occlusion, with no CAD model.

1.13 mmpose ADD-S · simulation · 50 FPS
2.42 mmpose ADD-S · real hardware · 37 FPS
0.997map F-score@5 mm · sim (0.950 real)
7.0–12.4×frame rate vs NeuralFeels · sim
Method & results
  • One map, every job: a single object-centric 3D Gaussian state serves training, rendering, frozen-map SDF pose tracking, reconstruction evaluation, and manipulation-facing geometry. It replaces the neural-implicit SDF as the shared representation for online, model-free visuo-tactile object SLAM.
  • Pose is recovered by a multi-residual Levenberg-Marquardt optimiser solving SE(3) against a frozen dual-sigma Gaussian-density anchor SDF, fusing synchronized RGB-D, tactile, and proprioceptive observations in one canonical frame.
  • A frame-zero branch generates a shape estimate from a single RGB crop with an image-to-3D model, then progressively replaces generated geometry with measured geometry as the episode progresses.
  • Evaluated on the FeelSight benchmark (8 simulation + 6 real-robot objects) across its simulation, real-robot, and occlusion splits, against the NeuralFeels and V-HOP baselines.
  • Pose mode: ADD-S 1.13 mm in simulation at 50 FPS and 2.42 mm on coverage-adequate real objects at 37 FPS, on a single RTX 5090. Map mode: observed-surface F-score@5 mm of 0.997 (sim) / 0.950 (real).
  • Lower pose error than NeuralFeels on every simulation aggregate at 7.0–12.4× the per-frame speed (5.8–8.3× on real); full-surface F-score 0.997 vs 0.908 on the matched object, cutting reconstruction time from ≈52 min to 12 s.
  • Edges V-HOP on occlusion-split ADD-S (1.45 vs 1.46 mm) at 48.8 vs 32 FPS, all with no supplied CAD model.
  • Developed inside Korea's national “Alchemist” humanoid programme (MOTIE), bringing visuo-tactile SLAM from research prototype to the Phase-2 full-scale humanoid.
3D Gaussian SplattingPyTorchCUDAgsplatLM SE(3)UR5eAllegro HandDIGIT tactileNVIDIA Omniverse
Thesis & code release upcoming, 2026.

PoP-SLAM

Point-cloud projection for dense visual SLAM

PaperSept – Dec 2024

Co-author · with S. Jung, J. Marchand, M. L. Paolicchi · Seoul National University

Replaces the per-pixel nearest-neighbour queries that bottleneck neural point-cloud SLAM with a projection-first pipeline: project ~15,000 neural points into the image plane by vectorised matrix multiplication, mask by multi-keyframe depth consistency, render. No volumetric queries.

0.75 cmbest ATE RMSE · TUM-RGBD
0.38 cmavg ATE RMSE · Replica
faster than Point-SLAM
Method & results
  • Outperforms Point-SLAM, NICE-SLAM, ESLAM, and SplaTAM on TUM-RGBD trajectory accuracy.
  • ~4 FPS on a single consumer RTX 4070; <3.3% overhead from point pruning.
  • Direct occlusion detection via multi-keyframe depth masking: retain only points consistent with measured depth across nearby keyframes.
PyTorchCUDAOpen3DTUM-RGBDReplica

GNSS-denied SLAM

LiDAR-camera fusion navigation for an outdoor robot without GPS

B.S. research2023 – 2024

B.S. thesis research · Villanova University

Where GPS fails, the robot must localise itself from what it can see. The main research project of the bachelor's: a full LiDAR-camera fusion navigation stack for a quad-wheel outdoor robot, built alongside a Ph.D. dissertation on autonomous localisation and navigation in GNSS-denied environments at Villanova University.

Method & results
  • Full ROS navigation stack on the quad-wheel platform: path planning and obstacle avoidance running on Arduino and Raspberry Pi for real-time control.
  • CNN-based feature extraction and point-cloud generation from fused LiDAR-camera data; visual odometry for motion estimates without GPS.
  • Real-time 3D environment mapping with computer-vision landmark identification and edge detection.
  • Probabilistic localisation: a 2D histogram filter with a 1D Kalman tracker over probabilistic motion models.
ROSLiDARVisual odometryCNN featuresHistogram filterKalman filterArduinoRaspberry Pi

Stretchable sEMG sensing

Jan 2024

PDMS + vapour-deposited silver-nanoparticle stretchable electromyography with CNN-GRU/ViT gesture classification. Winter research internship at the SNU Soft Robotics & Bionics Lab that seeded the M.S.

Research placement
Publications
GaussianFeels: Object-Centric Gaussian SLAM for Visuo-Tactile In-Hand ManipulationM.S. Thesis · Seoul National University · 2026release upcoming
Registering Gaussian Splats Without the Point-Cloud Detour: Accuracy, Representation Semantics, and a Negative Result on Hypothesis-Stage TransferK. Attri · engrXiv preprint · companion software: splatreg · 2026DOI 10.31224/7313 engrXiv page
No Single Basis Wins: A Cross-Family Study of Diffusion Feature Forecasting and the Limits of Training-Free Basis SelectionK. Attri · engrXiv preprint · companion software: HiCache++ · 2026DOI 10.31224/7309 engrXiv page
CERT: Certified Route Planning under Drifting Costs, Conformal Certificates, Sense-to-Certify, and the Price of StalenessK. Attri · engrXiv preprint · companion software: CERT-FLOW · 2026DOI 10.31224/7306 engrXiv page
ToothPrint: A Certified, Partial-Overlap-Robust System for Dental Biometric IdentificationK. Attri · engrXiv preprint · companion software: ToothPrint · 2026DOI 10.31224/7403 engrXiv page
PoP-SLAM: Point Cloud Projection for SLAMS. Jung, K. Attri, J. Marchand, M. L. Paolicchi · course project, SNU · 2024PDF
02Personal projects

Released & installable.

Five flagship systems with measured results, followed by a compact archive of earlier and supporting work.

splatreg

Register Gaussian splats.

v1.4.0 · BSD-3-Clause · pure PyTorch · CLI + API

Aligning independently captured 3D Gaussian-Splatting scans usually means falling back to point-cloud registration that throws away the splat structure. splatreg registers natively on the Gaussian representation (a Gaussian-SDF residual with a closed-form Jacobian over SE(3)/Sim(3)), then merges, or aligns without merging: the CLI bakes the recovered pose into the source so both scans stay separate PLYs in one frame. Baked-in transforms rotate the higher-order spherical-harmonic colour with the splat (real-basis Wigner-D); photometric refinement with exposure compensation handles the poses geometry cannot see; every builtin solve reports pose covariance for pose-graph weighting, never faked. Recall matches the GeoTransformer point-cloud baseline on official 3DMatch (91.5% mean / 93.5% pooled) and 3DLoMatch (72.5% / 74.4%) while adding the Sim(3) scale DoF the baseline lacks, and rotation lands 2.9× tighter than existing splat tools (5.2° vs 15.3°). The MAC maximal-clique seed handles contaminated correspondence sets, with the honest measured verdict kept: a wash on the official 3DMatch split, a decisive win on structured decoys.

official 3DMatch registration recall, 1279 pairs
91.5%
SH Wigner-rotation error vs an independent evaluator
2.4e-15
splat-merge Chamfer vs naïve concat
10.3 → 2.0 mm
photometric refine where geometry under-constrains
5° → 0.36°

CERT-FLOW

Certified route planning under drifting costs.

v1.1.0 · MIT · 256 core tests passing · 32 data-gated skips · 16 reproduction pipelines

A robot replanning through a world whose costs drift never knows how good its current route is once the map goes stale; classical planners silently trust the stale map. CERT-FLOW answers with a proof every round: a high-probability certificate LB ≤ OPT ≤ UB on the optimal route cost, built from age-weighted non-exchangeable conformal prediction over drift-adjusted residuals, and it spends paid sensing exactly where the certificate says the gap shrinks fastest. When the certificate proves the map tight, that proof licenses ns-to-µs preprocessed queries that self-expire the instant drift exceeds tolerance. Seven theorems (coverage through an impossibility result on lower bounds), validated on 17 synthetic regimes, game maps, and real traffic (METR-LA, PEMS-BAY); the failed hypotheses stay documented in the record.

coverage on every condition ever run; classical replanning 0.02 – 0.59
0.95 – 1.00
certificate-gated static cost query; 3.7 ms p50 full certified round, one CPU core
269 ns
lower sensing regret than freshness, uncertainty, or random at equal budget
2 – 3×

HiCache++

Diffusion acceleration by feature forecasting, honestly selected.

v1.2.1 · MIT · training-free · DMD calibrator merged into cache-dit · 16-repo accelerator family

Feature caches skip the network on most denoising steps and forecast the cached features instead. HiCache++ ships the exponential (Dynamic Mode Decomposition / Prony) basis, exact on the local feature-ODE class where polynomial bases (TaylorSeer, Hermite) diverge, and the honest finding the benchmarks forced: no single forecast basis wins across diffusion families. The exponential basis wins on flow-matching 3D generators; polynomials hold DiT-class denoising. So the product is the selector: backend auto backcasts a held-out snapshot with both bases at every compute step and serves whichever demonstrably wins, at zero extra model calls. The same study surfaced a benchmark-integrity find: a one-character sign error that left a published baseline anti-extrapolative yet invisible to every end-to-end metric, answered with directional closed-form regression tests. The exponential-basis DMD calibrator is now upstream: it was merged into vipshop/cache-dit (PR #1053, 2026-06-14) and ships in cache-dit v1.5.0, behind SGLang-Diffusion, vLLM-Omni, and ComfyUI. Also deployed through per-model adapters across TRELLIS, Hunyuan3D, and SAM 3D, plus three GPU-validated ComfyUI nodes (Hunyuan3D, TRELLIS, TRELLIS.2).

F-score at skip-interval 5, exponential vs polynomial arm, Hunyuan3D-2.1
0.860 vs 0.735
geometry-lossless (F1 = 1.000) through interval 6, SAM 3D Objects
1.56×
holdout auto detects basis misfit and serves the winning arm
120/120
+ The 16-repo accelerator family

ActionABI + ActionShift

Find the hidden contract between a policy and a robot.

C++20 forensic tool + Python 3.11 benchmark · MIT · shared seven-field contract grammar

A robot policy can emit the right numbers through the wrong interface and move confidently in the wrong direction. ActionABI attacks that failure offline: it recovers undocumented action-tensor semantics from logged trajectories, retains calibrated equivalence sets, and refuses to emit a converter when the evidence cannot identify one. ActionShift attacks it online: frozen ManiSkill policies face hidden permutations, signs, scales, target modes, frames, lag, and gripper conventions, then adapt through bounded probes. The pair shares one grammar and one scorer, with ActionABI's C++ evidence core running inside ActionShift's belief loop.

ambiguous synthetic cases correctly abstained, zero false uniques
25 / 25
PickCube success, no adaptation to pool-belief adaptation
0.000 → 0.987
fewer probe steps for DualABI at matched success
52%

mathlas

Airtight math tools an AI uses.

v1.5.0 · Apache-2.0 · 12 MCP tools · no LLM inside, no API key · official MCP registry · Glama grade A

Language models hallucinate theorems, and prose is not verification. mathlas is an MCP server of 12 deterministic, data-returning tools an AI agent drives: search over a 3.68M-document index (dense + BM25 + rank fusion), PSLQ constant identification, OEIS sequence lookup, and real Lean-kernel checks that now verify full proofs, returning the kernel's error verbatim so the agent can repair and re-call. A quantized laptop tier serves the same index from 1.9 GB at 2.4 s/query on 4 CPU threads, measured recall-lossless. The discipline is airtight-or-nothing: every verification tier returns an independently checkable fact or an honest nothing, with zero false positives measured across all tiers.

the same agent on 18 math tasks, with vs without mathlas
18/18 vs 15/18
Hit@20 vs TheoremSearch, on its own 110 human queries
59.1 vs 45.0
documents indexed; dual-channel R@10 0.999; 1.9 GB quantized tier
3.68M
More personal projects5 compact entries

stepback

Git time-travel for any AI coding agent.

v0.1.0 · MIT · Python 3.11+ · agent-agnostic filesystem checkpoints

AURA

The radiance-asset layer after 3DGS.

v0.1.0 · research preview · MIT · KHR + OpenUSD 26.03 export

CV object-detection web app

An early five-detector COCO comparison app built while learning open-source contribution workflows.

Deprecated practice project · 2024 · React + Flask
03Experience

Lab, field & industry.

2024 – 2026

Graduate Research Student

Soft Robotics & Bionics Laboratory, Seoul National University · Seoul, KR

GSFS Scholar. GaussianFeels thesis; PoP-SLAM; perception integration for the Phase-2 “Alchemist” humanoid (MOTIE).

  • Built GaussianFeels: online visuo-tactile reconstruction and pose tracking on an object-centric 3DGS map. Pose ADD-S 1.13 mm sim (50 FPS) / 2.42 mm real (37 FPS), beating NeuralFeels on every sim aggregate at 7.0–12.4× the frame rate, with no CAD model.
  • Co-developed PoP-SLAM: projection-first dense visual SLAM, 0.75 cm ATE RMSE on TUM-RGBD on a consumer GPU.
  • Leading integration of visuo-tactile SLAM and dexterous in-hand manipulation into the Phase-2 full-scale humanoid prototype of Korea's “Alchemist” programme.
2023 – 2024

Robotics & Mechatronics Researcher

Villanova University · Villanova, PA

SLAM for GNSS-denied navigation with a Ph.D. dissertation project: quad-wheel outdoor robot.

  • Full ROS navigation stack: LiDAR-camera fusion with CNN feature extraction and visual odometry; path planning and obstacle avoidance.
  • Probabilistic localisation (2D histogram filter + 1D Kalman tracker); Arduino and Raspberry Pi integration for real-time control.
Jan 2024

Undergraduate Research Intern

Soft Robotics & Bionics Lab, Seoul National University · Seoul, KR

Winter research internship: stretchable sEMG sensing with deep-learned gesture recognition (PDMS, AgNP; CNN-GRU/ViT).

Summer 2023

Indoor Farm Robotics Intern

Area2Farms · Arlington, VA

“Silo” vertical-farming automation: extruded-aluminium construction, pneumatics, industrial robotics, Arduino/Raspberry Pi, irrigation systems.

Summer 2022

Product Design Intern

Ampere LLC · Remote, USA

3D product modelling for consumer technology; structural-integrity and physics analysis.

Also held, Villanova
Distance Education OperatorA/V support, live-stream recording, and archiving for online course production.2021, 2023 – 2024
Collections & Stewardship TechnicianDigitisation, cataloguing, and preservation of rare and special collections for the university Digital Library.Jan – May 2022
04School

Four schools, three countries.

incoming
Ph.D., Mechanical Engineering
University of Central Florida
ORCGS Doctoral Fellow · Rehabilitation Engineering & Assistive Device Lab · Prof. Hwan Choi
from Aug 2026REAL lab
current
M.S., Mechanical Engineering
Seoul National University
GSFS Scholar · Soft Robotics & Bionics Laboratory · Prof. Yong-Lae Park
2024 – 2026
complete
B.S., Mechanical Engineering
Villanova University
Minor in Mechatronics · Concentration: Control & Dynamics
2020 – 2024Diploma
complete
Exchange year, Mechanical Engineering
Yonsei University
Controls · vibrations · circuit theory · probability
2022 – 2023
Stack

Perception & SLAM

3D Gaussian Splattingvisuo-tactile SLAMRGB-D reconstructionSE(3)/Sim(3) registrationpose trackingsensor fusion

ML & acceleration

PyTorchCUDA kernelsdiffusion / flow modelsimage-to-3Dfeature caching (DMD)differentiable rendering

Agents & formal methods

MCP serversdense + BM25 retrievalLean 4 kernelPSLQ / OEISfail-closed engineering gates

Robotics & hardware

ROSUR5eAllegro HandDIGIT tactileLiDAR + IMU + RTKaction-interface contractsArduino / Raspberry PiNVIDIA Omniverse

Languages & tools

PythonC/C++MATLABLaTeXSOLIDWORKSLinuxGit
05School projects

Built at university.

The SNU thesis cross-reference, two undergraduate flagships, and the earlier hands-on builds.

SNU · Graduate researchGaussianFeelsSNU M.S. thesis: real-time visuo-tactile 3D Gaussian SLAM for model-free in-hand reconstruction and 6-DoF pose tracking.Full research case study →2024 – 2026

EOD / GNSS-denied robot platform

B.S. laboratory research · Robotics & Mechatronics Researcher · Villanova University

B.S. research flagship2023 – 2024

A quad-wheel research robot for autonomous localisation and navigation without GPS. Built a ROS navigation stack with path planning and obstacle avoidance, used LiDAR-camera fusion for CNN features, point-cloud mapping, and visual odometry, and integrated Arduino and Raspberry Pi control for real-time operation.

Earlier builds
Arduino puzzle box2022

Randomised solution algorithm; glitter-spray penalty for wrong inputs.

3rd place, Villanova mechatronics. Four-person scratch build.

Custom stability firmware; multi-drone sync experiments.

Servo robotic arm2021

Servo-actuated arm programmed for pick-and-place.

Self-assembled 3D printer2021

Frame, wiring, firmware, slicer; full bring-up.

SOLIDWORKS scooter model2021

Four-person team; designed and 3D-printed a functional scooter.

Assistive wearable concept2020

3rd place, Villanova ICE competition.

Basketball outcome prediction2020

Python ML mini-project; three-person team.

06Contact

Write first.

krishiattriwork@gmail.com

Seoul, South Korea → Orlando, FL (Aug 2026)

Open to
Robotics / AI research collaborations
Internships in robot perception or 3D vision
Roles in SLAM, applied ML & manipulation