Abstract Capturing fine‐grained hand‐object interactions is challenging due to severe self‐occlusion from closely spaced fingers and the subtlety of in‐hand manipulation motions. Existing optical motion capture systems rely on expensive camera setups and extensive manual post‐processing, while low‐cost vision‐based methods often suffer from reduced accuracy and reliability under occlusion. To address these challenges, we present DexterCap, a low‐cost optical capture system for dexterous in‐hand manipulation. DexterCap uses dense, character‐coded marker patches to achieve robust tracking under severe self‐occlusion, together with an automated reconstruction pipeline that requires minimal manual effort. With DexterCap, we introduce DexterHand, a dataset of fine‐grained hand‐object interactions covering diverse manipulation behaviors and objects, from simple primitives to complex articulated objects such as a Rubik's Cube. We release the dataset and code to support future research on dexterous hand‐object interaction. Project website: https://pku-mocca.github.io/Dextercap-Page/
Liang et al. (2026) studied this question.