Levitation Simulator: Prototyping Ultrasonic Levitation Interfaces in Virtual Reality

Abstract

Figure 1: The Levitation Simulator allows to simulate interaction with a levitation interface in VR. Two user studies, comparing the real prototype (left) with the VR simulator (right), show that the VR simulation provides a good approximation of the interaction with the levitating particle in the real prototype. We share our Levitation Simulator as Open Source (www.ai8.unibayreuth.de/en/projects/Levisim), thereby democratizing levitation research and facilitating the design of applications for levitation interfaces, without the need for a levitation apparatus. ABSTRACTWe present the Levitation Simulator, a system that enables researchers and designers to iteratively develop and prototype levitation interface ideas in Virtual Reality. This includes user tests and formal experiments. We derive a model of the movement of a levitating particle in such an interface. Based on this, we develop an interactive simulation of the levitation interface in VR, which exhibits the dynamical properties of the real interface. The results of a FittsâȂŹ Law pointing study show that the Levitation Simulator enables performance, comparable to the real prototype. We developed the first two interactive games, dedicated for levitation interfaces: LeviShooter and BeadBounce, in the Levitation Simulator, and then implemented them on the real interface. Our results indicate that participants experienced similar levels of user engagement when playing the games, in the two environments. We share our Levitation Simulator as Open Source, thereby democra-Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored.

OptiTrap: Optimal Trap Trajectories for Acoustic Levitation Displays

“…While the dynamics of the system were considered, these were extremely simplified, using a model of acoustic trap forces and system dynamics that are only applicable for oscillating recti-linear trajectories along the vertical axis of the levitator. [Paneva et al 2020] proposed a generic system simulating the dynamics of a top-bottom levitation system. This operates as a forward model simulating the behaviour of the particle given a specific path for the traps, but unlike our approach it does not address the inverse problem.…”

“…4.1.1 Existing Models of the Trap-Particle Dynamics. Simple spring models have been used extensively [Fushimi et al 2020[Fushimi et al , 2018Paneva et al 2020], modelling trapping forces according to a stiffness parameter K 𝑖 , that is, with forces being proportional to the distance of the particle to the centre of the trap:…”

TipTrap: A Co-located Direct Manipulation Technique for Acoustically Levitated Content.

“…LeviCursor [3] explores the use of a levitated particle as a 3D cursor, also using a remote ray casting technique. These distant interactions techniques have been adopted by related applications, such as LeviLoop [32] or the shooting game in [37].…”

“…This has attracted the interest of the HCI community, which has started to explore applications [31,34,35,37] and interaction techniques, such as Point-and-Shake [13] for particle selection or LeviCursor [3] for manipulation. However, such interaction techniques only allow interaction at a distance.…”

ArticuLev: An Integrated Self-Assembly Pipeline for Articulated Multi-Bead Levitation Primitives

“…Most recently, continuous, fully volumetric content has also been demonstrated using single [9] or multiple [12] quickly moving beads to exploit the persistence of vision (PoV) effect. Inspired by the potential of acoustic levitation, the HCI community has started to explore interaction issues around levitation interfaces [7,1], geometry and content creation [19,6] or even simulators [26].…”