# Hand-Surface Interaction Fields

TactoHand unifies contact, proximity and 3D vertex force into dense fields on the hand surface inferred from monocular video, removing the need for the specialized hardware that tactile collection requires. A temporal transformer aggregates visual evidence across frames, and a differentiable rigid-body layer ties predicted forces to observed object motion. On HOCap, excluded from training, contact Macro-F1 reaches 50.5 against 18.0 for HACO, and physics supervision lowers the temporal variant's rollout position error from 5.7 cm to 3.3 cm.

TactoHand unifies contact, proximity and 3D vertex force into dense fields on the hand surface inferred from monocular video, removing the need for the specialized hardware that tactile collection requires. A temporal transformer aggregates visual evidence across frames, and a differentiable rigid-body layer ties predicted forces to observed object motion. On HOCap, excluded from training, contact Macro-F1 reaches 50.5 against 18.0 for HACO, and physics supervision lowers the temporal variant's rollout position error from 5.7 cm to 3.3 cm.