# HaloTouch: Using IR Multi-path Interference to Support Touch Interactions With General Surfaces

arXiv: https://arxiv.org/abs/2503.01197 · HTML: https://mlsanity.com/paper/2503.01197/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 3 Mar 2025.

## Built on by (most cited first, 2 of 2)

- [SurfaceXR: Fusing Smartwatch IMUs and Egocentric Hand Pose for Seamless Surface Interactions](https://mlsanity.com/paper/2603.19529/) (2026)
- [EclipseTouch: Touch Segmentation on Ad Hoc Surfaces using Worn Infrared Shadow Casting](https://mlsanity.com/paper/2509.03430/) (2025)

## Abstract (arXiv)

Sensing touch on arbitrary surfaces has long been a goal of ubiquitous computing, but often requires instrumenting the surface. Depth camera-based systems have emerged as a promising solution for minimizing instrumentation, but at the cost of high touch-down detection error rates, high touch latency, and high minimum hover distance, limiting them to basic tasks. We developed HaloTouch, a vision-based system which exploits a multipath interference effect from an off-the-shelf time-of-flight depth camera to enable fast, accurate touch interactions on general surfaces. HaloTouch achieves a 99.2% touch-down detection accuracy across various materials, with a motion-to-photon latency of 150 ms. With a brief (20s) user-specific calibration, HaloTouch supports millimeter-accurate hover sensing as well as continuous pressure sensing. We conducted a user study with 12 participants, including a typing task demonstrating text input at 26.3 AWPM. HaloTouch shows promise for more robust, dynamic touch interactions without instrumenting surfaces or adding hardware to users.