Boxer: a multimodal collision technique for virtual objects

Virtual collision techniques are interaction techniques for invoking discrete events in a virtual scene, e.g. throwing, pushing, or pulling an object with a pointer. The conventional approach involves detecting collisions as soon as the pointer makes contact with the object. Furthermore, in general, motor patterns can only be adjusted based on visual feedback. The paper presents a multimodal technique based on the principle that collisions should be aligned with the most salient sensory feedback. Boxer (1) triggers a collision at the moment where the pointer's speed reaches a minimum after first contact and (2) is synchronized with vibrotactile stimuli presented to the hand controlling the pointer. Boxer was compared with the conventional technique in two user studies (with temporal pointing and virtual batting). Boxer improved spatial precision in collisions by 26.7 % while accuracy was compromised under some task conditions. No difference was found in temporal precision. Possibilities for improving virtual collision techniques are discussed.