Multisensory gestural modality is a sensorial modality as well as an action modality. It integrates proprioceptive, tactile and kinesthetic perception, and any form of motor action. This modality plays a fundamental role in any instrumental activity : sculpture, violin playing, vehicle driving... ACROE works on three aspects :
1. Quantitative characterization of gestural activity
- Digital gesture (fixed wrist) : it is the gesture of the sculptor, the pianist, the violin player, the dentist. It is characterized by short movements (3cm), high precision (2 mm, 10 mN) and strong forces (80 N),
- Local transportation gesture (fixed elbow) : it is the proximity placement gesture done by forearm movement with about 30 cm amplitude and rather low precision and force (0,5 cm, 10 N),
- Broad movement gesture (fixed shoulder, or fixed hip) : it is a low precision (5 cm, 100 N) approaching gesture, done by arm or body movement starting at 60 cm.
2. Qualitative and functional characterization of gestural activity
Three different functions can be distinguished in gestural activity (cf. "Le geste...", Cadoz in the ACROE-ICA's library) :
- an epistemic function -> the gesture is used to acquire knowledge of something (object, material, surface...)
- a semiotic function -> the gesture is used to make something known to others : to point, to communicate...
- an ergotic function -> the gesture is used to move, to alter, or to build material objects.
3. Gestural interaction models
An important part of ACROE's work is developing physically-based models to use in gestural effects rendering via force-feedback gestural systems : feeling of rigidity, elasticity, inertia distribution, adherence, roughness, collapses, shape feeling, texture feeling... as well as studying gestural anamorphosis.