From Contact to Action: Fold-Contact Affordances for Cloth Unfolding

Manipulation depends on physical relationships that visible shape alone can leave ambiguous. Cloth unfolding makes this problem concrete: the same overhead silhouette can conceal different arrangements of folds and support. We study how complementary sensing can expose support cues and make them useful for action. A transparent-table dual-arm setup pairs a top segmentation mask with a bottom contact mask. We derive fold residual, contact overlap, fold-contact frontier, and silhouette-edge maps for an attention encoder and a residual action prior. An online linear, contextual-bandit-style scorer adapts the prior's target ranking from reward, self-supervised unfolding progress, or their mixture. In the long-horizon comparison, raw dual-view pixels improve flatness over a top-only policy; affordance channels reduce folded area by 82.2% relative to raw dual masks in a fast screen; and the reward-bandit bottom-view scorer performs best in the 21-run residual-prior ablation, with within-panel geometry score $0.840\pm 0.047$. These findings suggest a design principle for cloth unfolding: organize perception around support relationships and connect that representation to target selection through interaction feedback.