We explore the concept of a Spherical World in Miniature (SWIM) for discrete locomotion in Virtual Reality (VR). A SWIM wraps a planar WIM around a physically embodied sphere and thereby implements the metaphor of a tangible Tiny Planet that can be rotated and moved, enabling scrolling, scaling, and avatar teleportation. The scaling factor is set according to the sphere's distance from the head-mounted display (HMD), while rotation moves the current viewing window. Teleportation is triggered with a dwell time when looking at the sphere and keeping it still. In a lab study (N=20), we compare our SWIM implementation to a planar WIM with an established VR controller technique using physical buttons. We test both concepts in a navigation task and also investigate the effects of two different screen sizes. Our results show that the SWIM, despite its less direct geometrical transformation, performed superior in most evaluations. It outperformed the planar WIM not only in terms of task completion time (TCT) and accuracy but also in subjective ratings.

We investigate the use of a handheld spherical object as a controller for locomotion in VR. Rotating the object controls avatar movement in two different ways: As a zero order controller, it is continuously rotated to the target position as if rolling a ball on the floor. As a first order controller, it is tilted like a joystick to determine the direction and speed of movement. We describe how our prototype was built from low-cost commercially available hardware and discuss our design decisions. Then we evaluate both locomotion techniques in a user study (N=20) and compare them to established methods using handheld VR controllers. Our prototype matched and in some cases outperformed these methods regarding task time and accuracy. All results were obtained without any usage instructions, indicating easy learnability. Some of our insights may transfer to interaction with other naturally shaped objects in VR experiences.

In this paper, we explore how a familiarly shaped object can serve as a physical proxy to manipulate virtual objects in Augmented Reality (AR) environments. Using the example of a tangible, handheld sphere, we demonstrate how irregularly shaped virtual objects can be selected, transformed, and released. After a brief description of the implementation of the tangible proxy, we present a buttonless interaction technique suited to the characteristics of the sphere. In a user study (N = 30), we compare our approach with three different controller-based methods that increasingly rely on physical buttons. As a use case, we focused on an alignment task that had to be completed in mid-air as well as on a flat surface. Results show that our concept has advantages over two of the controller-based methods regarding task completion time and user ratings. Our findings inform research on integrating tangible interaction into AR experiences.

The emerging possibilities of data analysis and exploration in virtual reality raise the question of how users can be best supported during such interactions. Spherical visualizations allow for convenient exploration of certain types of data. Our tangible sphere, exactly aligned with the sphere visualizations shown in VR, implements a very natural way of interaction and utilizes senses and skills trained in the real world. This work is motivated by the prospect to create in VR a low-cost, tangible, robust, handheld spherical display that would be difficult or impossible to implement as a physical display. Our concept enables it to gain insights about the impact of a fully tangible embodiment of a virtual object on task performance, comprehension of patterns, and user behavior. After a description of the implementation we discuss the advantages and disadvantages of our approach, taking into account different handheld spherical displays utilizing outside and inside projection.

Recent developments in the commercialization of virtual reality open up many opportunities for enhancing human interaction with three-dimensional objects and visualizations. Spherical visualizations allow for convenient exploration of certain types of data. Our tangible sphere, exactly aligned with the sphere visualizations shown in VR, implements a very natural way of interaction and utilizes senses and skills trained in the real world. In a lab study, we investigate the effects of the perception of actually holding a virtual spherical visualization in hands. As use cases, we focus on surface visualizations that benefit from or require a rounded shape. We compared the usage of two differently sized acrylic glass spheres to a related interaction technique that utilizes VR controllers as proxies. On the one hand, our work is motivated by the ability to create in VR a tangible, lightweight, handheld spherical display that can hardly be realized in reality. On the other hand, gaining insights about the impact of a fully tangible embodiment of a virtual object on task performance, comprehension of patterns, and user behavior is important in its own right. After a description of the implementation we discuss the advantages and disadvantages of our approach, taking into account different handheld spherical displays utilizing outside and inside projection.