Hardware-accelerated real-time simulation of arbitrary visual fields

Abstract

Recent advancements in computer graphics hardware have made it possible to develop hardware-accelerated real-time imaging displays. This poster presents technical details of an OpenGL multitexturing approach for real-time simulation of arbitrary visual fields over a still image. Mipmapping facilitates in-hardware dyadic (power-of-two) degradation of the image to serve as the low-resolution periphery. Multitexture compositing provides a mechanism to combine the image's high-resolution pixels within a window (of arbitrary shape). The poster presents code examples to achieve gaze-contingent movement of the high-resolution window over a smoothly or coarsely degraded version of the image background as shown in Figure 1.To test the display rate of the multitexturing approach, the runway image (1024 × 512) of Figure 1 was shown in a 1280 × 1024 display window (sufficient to fill a 17'' flat panel). Image rendering was timed in code as the foveal Region Of Interest (ROI) was made to move continuously over the image (diagonally from the top-right corner to the bottom-left, maintaining the full ROI within the window). Sustained display rates (in frames per second) reported by the timer averaged 120 fps on three different platforms.The multitexturing display was successfully adapted to a gaze-contingent application using the Tobii eye tracker for real-time gaze measurement. The Tobii eye tracker can be configured in several ways, one of which is acting as a server for a (possibly remote) eye tracking client application. Communication between client and server occurs over TCP/IP. A Linux PC, used for most of the eye tracker code testing, was set up with dual monitors, as shown in Figure 1, with the Tobii server running on a Windows 2000 PC.