The Visual Display Transformation for Virtual Reality

The visual display transformation for virtual reality (VR) systems is typically much more complex than the standard viewing transformation discussed in the literature for conventional computer..

A National Research Agenda for Virtual Reality: Report by the National Research Council Committee on VR R&D

In 1992, at the request of a consortium of federal agencies, the National Research Council established a committee to "recommand a national research and development agenda in the area of virtual reality" to set U.S. government R&D funding priorities for virtual reality (VR) for the next decade...

Implementation of Flying, Scaling, and Grabbing in Virtual Worlds

In a virtual world viewed with a head-mounted display, the user may wish to perform certain actions under the control of a manual input device. The most important of these actions are flying through the world, scaling the world, and grabbing objects. This paper shows how these actions can be precisely specified with frame-to-frame invariants, and how the code to implement the actions can be derived from the invariants by algebraic manipulation. INTRODUCTION Wearing a Head-Mounted Display (HMD) gives a human user the sensation of being inside a three-dimensional, computersimulated world. Because the HMD replaces the sights and sounds of the real world with a computer-generated virtual world, this synthesized world is called virtual reality. The virtual world surrounding the user is defined by a graphics database called a model, which gives the colors and coordinates for each of the polygons making up the virtual world. The polygons making up the virtual world are normally grouped into e..

for Virtual Reality

The visual display transformation for virtual reality (VR) systems is typically much more complex than the standard viewing transformation discussed in the literature for conventional computer graphics. The process can be represented as a series of transformations, some of which contain parameters that must match the physical configuration of the system hardware and the userÕs body. Because of the number and complexity of the transformations, a systematic approach and a thorough understanding of the mathematical models involved is essential. This paper presents a complete model for the visual display transformation for a VR system; that is, the series of transformations used to map points from object coordinates to screen coordinates. Virtual objects are typically defined in an object-centered coordinate system (CS), but must be displayed using the screen-centered CSs of the two screens of a head-mounted display (HMD). This particular algorithm for the VR display computation allows multiple users to independently change position, orientation, and scale within the virtual world, allows users to pick up and move virtual objects, uses the measurements from a head tracker to immerse the user in the virtual world, provides an adjustable eye separation for generating two stereoscopic images, uses the off-center perspective projection required by many HMDs, and compensates for the optical distortio