Subjective Usefulness of CAVE and Fish Tank VR Display Systems for a Scientific Visualization Application

Abstract

The scientific visualization community increasingly uses VR display systems, but useful interaction paradigms for these systems are still an active research subject. It can be helpful to know the relative merits of different VR systems for different applications and tasks. In this paper, we report on the subjective usefulness of two virtual reality (VR) display systems, a CAVE and a Fish Tank VR display, for a scientific visualization application (see Figure 1). We conducted an anecdotal study to learn five domainexpert users’ impressions about the relative usefulness of the two VR systems for their purposes of using the application. Most of the users preferred the Fish Tank display because of perceived display resolution, crispness, brightness and more comfortable use. Whereas, they found the larger scale of objects, expanded field of view, and suitability for gestural expressions and natural interaction in the CAVE more useful. The term “Fish Tank VR” is used to describe desktop systems that display stereo image of a 3D scene, which is viewed on a monitor using perspective projection coupled to the head position of the observer [Ware et al. 1993]. A CAVE is a room-size, immersive VR display environment where the stereoscopic view of the virtual world is generated according to the user’s head position and orientation [Cruz-Neira et al. 1993]. Some related work compares Fish Tank VR displays with Head Mounted Stereo Displays (HMD) and conventional desktop displays. In [Ware et al. 1993; Arthur et al. 1993], the authors compare Fish Tank VR with an HMD and conventional desktop systems. [Pausch et al. 1997] showed that HMDs can improve performance, compared to conventional desktop systems, in a generic search task when the target is not present. However, a later study showed that these findings do not apply to desktop VR; Fish Tank VR and desktop VR have a significant advantage over HMD VR in performing a generic search task [Robertson et al. 1997]. [Bowman et al. 2001] compared HMD with Tabletop (workbench) and CAVE systems for search and rotation tasks respectively They found that HMD users performed significantly better than CAVE users for a natural rotation task. For a difficult search task, they also showed that subjects perform differently depending on which display they encountered first. Bowman and his colleagues’ work shares similar motivations to ours. We go beyond their work with a direct comparison of CAVE and Fish Tank VR platforms. Also, most of previous studies have evaluated VR systems by looking at user performance for a few generic tasks such as rotation and visual search on experiment specific, simple applications. For most of the real visualization applications it may be difficult to reduce the interactions into a set of simple, generic tasks. Consequently, it is not clear how well the results of these studies apply to real visualization applications. This point is elucidated in a recent study that presented the importance of application specific user studies using tasks that reflect end user’s needs [Swan II et al. 2003]. In this study, the authors compare user performance for an application specific task across desktop, CAVE, workbench and display wall platforms. They found that the users performed tasks fastest using the desktop and slowest usFigure 1: The visualization application running in the CAVE (left image) and on the Fish Tank VR display (right image).