Modular Virtual Reality Visualization Tools
Wes Bethel LBL Report Number 36693, UC 405
We describe a collection of tools designed to be used in a Modular Visualization Environment (MVE) that facilitate the use of a Virtual Reality (VR) input device. VR input devices provide the means to easily and intuitively specify information which is three- or six-dimensional. Many scientific visualization tasks require this type of information. Our goal is to reduce the user interface complexity by employing a six-dimensional input device to specify six-dimensional data in scientific visualization. In the following sections, we describe relevant previous work and the functions supported by tools: device input, camera positioning, object transformations and developer's tools.
While the debate continues over whether or not the term "Virtual Reality" is an oxymoron or pleonasm, those of us tasked with developing or using visualization software more often than not must eschew this largely philosophical debate and focus our attention on more practical matters: usable software and scientific progress.
VR implementations range from fully immersive to desktop systems . The goal of each of these implementations is to provide a user interface in which a human can interact with a computer model in a way which is intuitive, "easy to use", interesting and engaging. We describe an approach to desktop VR geared towards the scientific user of MVE's that combine inexpensive yet practical VR input devices with a methodology for using the data generated by these devices in a variety of ways. For example, a tracker could be used in one context to position a viewpoint, but in another, to orient a slice plane.
Most VR input devices generate information which is six-dimensional: position and orientation. Along with that information, many have one or more buttons that can be used to generate boolean events. The methodology presented shows one way to manage this type of input, and capitalizes on the strengths of MVE's by allowing the user freedom of choice about the way in which the VR input device data is used in the visualization network. The benefits of MVE's which are of primary relevance are reusable software components and support for computing in a heterogeneous networked environment.
LBL-36693 Postscript version.