In this article we investigate the potential of using visuo-haptic illusions in Virtual Reality environment to learn motor skills in a real environment. We report on an empirical study where 20 participants perform a multi-object pick-and-place task. The results show that although users do not perform the same motion trajectories in the virtual and real environments, skills acquired in VR augmented with visuo-haptic illusions can be successfully reused in a real environment: There is a high amount of skill transfer (78.5%), similar to the one obtained in an optimal real training environment (82.4%); Finally, participants did not notice the illusion and were enthusiastic about the VR environment. Our findings invite designers and researchers to consider visuo-haptic illusions to help operators to learn motor skills in a cost-effective environment. CCS CONCEPTS• Software and its engineering → Virtual worlds training simulations; • Hardware → Tactile and hand-based interfaces;• Human-centered computing → Empirical studies in HCI.

Hand redirection is a visuo-haptic illusion offering rich haptic feedback in Virtual Reality while using a limited number of physical objects. This technique relies on a redirection function which determines the virtual hand position depending on the physical hand position. In this paper, we extend the design space of the Handredirection technique by generalizing this redirection function. A user study compares 6 redirection functions. Our results suggest that the redirection function does not deteriorate the illusion offering more flexibility and control to designer over the hand trajectory and avoid collisions. CCS CONCEPTS• Human-centered computing → HCI theory, concepts and models; Pointing.

Visuo-haptic illusions, such as Hand Redirection, offer rich haptic feedback in Virtual Reality while using a limited number of physical objects. In this paper, we extend the design space for these illusions by generalizing the redirection function. A user study compares 6 redirection functions. Our results suggest that the redirection function has no influence on the illusion breakup. They also suggest that the designer can freely manipulate the redirection function for example to avoid collisions. RÉSUMÉLes illusions visuo-haptiques, telles que la redirection de la main (Hand Redirection) offrent un retour haptique riche en réalité virtuelle bien qu'utilisant un nombre limité d'objets physiques. Dans cet article, nous élargissons l'espace de conception de ces illusions en généralisant la fonction de redirection. Une étude utilisateur compare 6 fonctions de redirections. Nos résultats suggèrent que la fonction de redirection n'a pas d'influence sur la rupture de l'illusion. Ils suggèrent également que le concepteur peut manipuler librement la fonction de redirection par exemple pour éviter des collisions. CCS CONCEPTS• Human-centered computing → HCI design and evaluation methods; Virtual reality.