We report the findings of a study designed to evaluate the effect of stereopsis and field of regard (FOR) in two different mixed reality (MR) simulation platforms: a head-mounted display (HMD) and a CAVE. We compared the performance of participants on two levels of stereopsis (mono and stereo) and two levels of FOR (90 degrees and 270 degrees) using a variety of scientific visualization tasks. Among the findings, we observed that not all the effects were consistent between the platforms. Stereo alone or in combination with higher FOR improved completion time on both platforms. However, adding stereo solely reduced the accuracy of the participants on the CAVE and improved on the HMD. Our findings extend prior knowledge on the contribution of visual fidelity components and suggests potential limits on MR simulation between platforms.

Volume visualization is an important technique for analyzing datasets from a variety of different scientific domains. Volume data analysis is inherently difficult because volumes are three-dimensional, dense, and unfamiliar, requiring scientists to precisely control the viewpoint and to make precise spatial judgments. Researchers have proposed that more immersive (higher fidelity) VR systems might improve task performance with volume datasets, and significant results tied to different components of display fidelity have been reported. However, more information is needed to generalize these results to different task types, domains, and rendering styles. We visualized isosurfaces extracted from synchrotron microscopic computed tomography (SR-μCT) scans of beetles, in a CAVE-like display. We ran a controlled experiment evaluating the effects of three components of system fidelity (field of regard, stereoscopy, and head tracking) on a variety of abstract task categories that are applicable to various scientific domains, and also compared our results with those from our prior experiment using 3D texture-based rendering. We report many significant findings. For example, for search and spatial judgment tasks with isosurface visualization, a stereoscopic display provides better performance, but for tasks with 3D texture-based rendering, displays with higher field of regard were more effective, independent of the levels of the other display components. We also found that systems with high field of regard and head tracking improve performance in spatial judgment tasks. Our results extend existing knowledge and produce new guidelines for designing VR systems to improve the effectiveness of volume data analysis.