Shape Aware Haptic Retargeting for Accurate Hand Interactions

Studying the Role of Self and External Touch in the Appropriation of Dysmorphic Hands

“…In addition, this mismatch might hinder the design of ST interactions based on augmented bodies [15,16,38], and limit the capacity to handle natural ST interactions, forcing the VR applications' designers to prevent intentional or accidental selftouch contacts in order to preserve immersion. Haptic retargeting is a technique designed in order to overcome visual and tactile contact position discrepancies [5,6,11,25,32,64], essentially consisting in introducing an offset between the real control and its virtual display, in order to match visual and tactile contact positions. Even if mostly employed to match tactile and visual props, this technique has been utilized in previous studies to match visual and tactile feedback of dysmorphic bodies for ET [22,24,52] and ST [34,44] stimulation.…”

“…During the visuotactile stimulation phase for the dysmorphic appearance conditions, the virtual brush-controller position was retargeted in order to match the visual and tactile contact positions between hand and brush-tip, despite the virtual and real hand's morphological differences (matching tactile positions for each condition are shown in Figure 1). For that purpose, we developed an algorithm adapted from previous research [5,32], which calculated at every frame the appropriate virtual brush position. The execution of the algorithm can be divided into three parts: finger level, hand level and global level.…”

“…Firstly, our experiment restricted the haptic stimulation to a continuous single contact point. In order to provide a completely free self-tactile feedback, more research is required to find solutions to more complex tactile interaction, such as multi-contact point interaction (similar to [32]) or self-tactile stimulation with the hand directly. Secondly, in this experiment the tactile stimulation was restricted to a simple linear movement, this was made to control that the tactile stimulation would be identical among trials, participants and conditions.…”

“…These discrepancies might prevent (i) the elicitation of the SoBO [9], (ii) the capacity to offer realistic ST interactions, or (iii) the design of body-based interactions through body augmentations [15,16,38]. To tackle the limitation of mismatching body contact, some studies [34,44] introduced the potential use of haptic retargeting techniques [5,11,32,64], consisting in applying an offset between the tracked body-part and its virtual counterpart.…”