Materialized virtual touch: mid-air haptic rendering in extended reality

Abstract

Tactile sensations play a major role in recognizing the existence and shape of virtual objects. Haptic rendering algorithms can create a sense of touch to provide the presence of virtual objects in XR applications. In addition, contact-based end-effectors such as gripper VR controllers or pen-type haptic devices are used for object interaction, and they can provide vibrotactile sensation and kinesthetic sensation. However, they have limitations on the user's hand posture and motion when the hand tracker is coupled to contact-based haptic devices. Recently, mid-air haptic technology combined with motion tracking technology produces a vibrotactile sensation to the user's unadorned hands without any contact-based end-effectors. This dissertation introduces the concept of materialized virtual touch related to collision presence and shape presence resulting from touching a virtual object. To introduce materialized virtual touch in XR applications, we develop mid-air haptic algorithms to create the presence of tactile touch in time-critical applications such as particle simulation and volume data exploration. First, we propose a tactile rendering algorithm to estimate the target pressure field using amplitude modulation. Second, we present the tactile pattern rendering to provide a shape perception from the cross-sectional data of the volume. For both applications, we verify that our algorithm runs at reliable refresh rates under the XR environment, and that the materialized virtual touch can provide collision and shape perception through user studies.