Viewing a Graph in a Virtual Reality Display is Three Times as Good as a 2D Diagram

An experiment is reported which tests whether network information is more effectively displayed in a three dimensional space than in a two dimensional space. The experimental task is to trace a path in a network and the experiment is carried out in 2D, in a 3D stereo view, in a 2D view with head coupled perspective, and in a 3D stereo view with head coupled perspective; this last condition creates a localized virtual reality display. The results show that the motion parallax obtained from the head coupling of perspective is more important than stereopsis in revealing structural information. Overall the results show that three times as much information can be perceived in the head coupled stereo view as in the 2D view

Interactive Visual Analytics for Large-scale Particle Simulations

Particle based model simulations are widely used in scientific visualization. In cosmology, particles are used to simulate the evolution of dark matter in the universe. Clusters of particles (that have special statistical properties) are called halos. From a visualization point of view, halos are clusters of particles, each having a position, mass and velocity in three dimensional space, and they can be represented as point clouds that contain various structures of geometric interest such as filaments, membranes, satellite of points, clusters, and cluster of clusters. The thesis investigates methods for interacting with large scale data-sets represented as point clouds. The work mostly aims at the interactive visualization of cosmological simulation based on large particle systems. The study consists of three components: a) two human factors experiments into the perceptual factors that make it possible to see features in point clouds; b) the design and implementation of a user interface making it possible to rapidly navigate through and visualize features in the point cloud, c) software development and integration to support visualization

Travails in the third dimension: a critical evaluation of three-dimensional geographical visualization

Several broad questions are posed about the role of the third dimension in data visualization. First, how far have we come in developing effective 3D displays for the analysis of spatial and other data? Second, when is it appropriate to use 3D techniques in visualising data, which 3D techniques are most appropriate for particular applications, and when might 2D approaches be more appropriate? (Indeed, is 3D always better than 2D?) Third, what can we learn from other communities in which 3D graphics and visualization technologies have been developed? And finally, what are the key R&D challenges in making effective use of the third dimension for visualising data across the spatial and related sciences? Answers to these questions will be based on several lines of evidence: the extensive literature on data and information visualization; visual perception research; computer games technology; and the author’s experiments with a prototype 3D data visualization system

Travails in the third dimension: a critical evaluation of three-dimensional geographical visualization

Several broad questions are posed about the role of the third dimension in data visualization. First, how far have we come in developing effective 3D displays for the analysis of spatial and other data? Second, when is it appropriate to use 3D techniques in visualising data, which 3D techniques are most appropriate for particular applications, and when might 2D approaches be more appropriate? (Indeed, is 3D always better than 2D?) Third, what can we learn from other communities in which 3D graphics and visualization technologies have been developed? And finally, what are the key R&D challenges in making effective use of the third dimension for visualising data across the spatial and related sciences? Answers to these questions will be based on several lines of evidence: the extensive literature on data and information visualization; visual perception research; computer games technology; and the author’s experiments with a prototype 3D data visualization system

An Empirical Evaluation of Visual Cues for 3D Flow Field Perception

Three-dimensional vector fields are common datasets throughout the sciences. They often represent physical phenomena that are largely invisible to us in the real world, like wind patterns and ocean currents. Computer-aided visualization is a powerful tool that can represent data in any way we choose through digital graphics. Visualizing 3D vector fields is inherently difficult due to issues such as visual clutter, self-occlusion, and the difficulty of providing depth cues that adequately support the perception of flow direction in 3D space. Cutting planes are often used to overcome these issues by presenting slices of data that are more cognitively manageable. The existing literature provides many techniques for visualizing the flow through these cutting planes; however, there is a lack of empirical studies focused on the underlying perceptual cues that make popular techniques successful. The most valuable depth cue for the perception of other kinds of 3D data, notably 3D networks and 3D point clouds, is structure-from-motion (also called the Kinetic Depth Effect); another powerful depth cue is stereoscopic viewing, but none of these cues have been fully examined in the context of flow visualization. This dissertation presents a series of quantitative human factors studies that evaluate depth and direction cues in the context of cutting plane glyph designs for exploring and analyzing 3D flow fields. The results of the studies are distilled into a set of design guidelines to improve the effectiveness of 3D flow field visualizations, and those guidelines are implemented as an immersive, interactive 3D flow visualization proof-of-concept application

An interactive 3D medical visualization system based on a light field display

This paper presents a prototype medical data visualization system exploiting a light field display and custom direct volume rendering techniques to enhance understanding of massive volumetric data, such as CT, MRI, and PET scans. The system can be integrated with standard medical image archives and extends the capabilities of current radiology workstations by supporting real-time rendering of volumes of potentially unlimited size on light field displays generating dynamic observer-independent light fields. The system allows multiple untracked naked-eye users in a sufficiently large interaction area to coherently perceive rendered volumes as real objects, with stereo and motion parallax cues. In this way, an effective collaborative analysis of volumetric data can be achieved. Evaluation tests demonstrate the usefulness of the generated depth cues and the improved performance in understanding complex spatial structures with respect to standard techniques.883-893Pubblicat

An evaluation of reconstruction filters for a path-searching task in 3D

The choice of reconstruction filter used to interpolate between sample points when generating images from volumetric data sets can have an impact on image quality. There are a range of reconstruction filters as well as methods to determine the quality of these filters. While it is well documented that stereoscopy can improve the performance of spatial search tasks, it is not clear how artifacts introduced by the choice of reconstruction filter will impact the performance of these tasks. In this study we report the results of a path-tracing experiment where we assess the effectiveness of stereoscopy and three reconstruction filters in terms of accuracy and response time. Our results suggest that the reconstruction filter can have a significant effect on path-tracing tasks and that stereoscopy can significantly improve accuracy results whilst slightly increasing response time

Abstract Data Visualisation in Mobile VR Platforms

Data visualisation, as a key tool in data understanding, is widely used in science and everyday life. In order data visualisation to be effective, perceptual factors and the characteristics of the display interface play a crucial role. Virtual Reality is nowadays accepted as a valid medium for scientific visualisation, because of its inherent characteristics of real-world emulation and intuitive interaction. However, the use of VR in abstract data visualisation is still limited. In this research, I investigate the use and suitability of mobile phone-based Virtual Reality as a medium for abstract data visualisation. I develop a prototype VR Android application and visualise data using the Scatterplot and Parallel Coordinates methods. After that, I conduct a user study to compare the effectiveness of the mobile VR application compared to a similar screen-based one by implementing some data exploration scenarios. The study results, while not being statistically significant, show improved accuracy and speed in the mobile VR visualisation application. The main conclusions are two-fold: Virtual Reality is beneficial for abstract data visualisation, even in the case of limited processing power and display resolution. Mobile VR, an affordable alternative to expensive desktop VR set-ups can be utilized as a data visualisation platform