Multiresolution techniques on a parallel multidisplay multiresolution image compositing system.

摘要

In most computer graphics applications resolution is a tradeoff. Using low-resolution images provide a low quality display, but typically allow higher frame rates because less data needs to be computed. High-resolution images, on the other hand, give the best display, yet are hindered by slower refresh times and thus limit user interactivity. Low image quality and low user interactivity are both detriments to computer graphics visualization applications. The question then is what can be done to minimize this impact.; The aim of this dissertation is to explore how to use multiresolution in order to provide the best balance between image quality and user interactivity on a parallel multidisplay multiresolution image compositing system with antialiasing called the Metabuffer. The architecture of the Metabuffer, a simulator written in C++, and a Beowulf cluster based emulator are fully described in this dissertation. Additional supporting hardware and software detailed in this document include an algorithm to partition data sets into Metabuffer viewports and a wireless visualization control device.; Using the Beowulf cluster based Metabuffer emulator, two multiresolution techniques are studied: progressive image composition and foveated vision. Progressive image composition allows the user to rapidly change view points without immediately moving data between PCs. Instead, the resolution of each PC's viewport adjusts in order to cover the visible polygons for which it is responsible. The larger, low-resolution viewports have lower image quality, but the user sees no drop in frame rate. Over time, the PCs can readjust their data in order to shrink their viewports and provide high-resolution imagery. Foveated vision allows computing resources to be concentrated only where the user is actually focused. Human peripheral vision cannot discern high levels of detail. Rendering the periphery with a low polygon count using a few low-resolution viewports allows the majority of the machines to render high-resolution viewports only where the user (or users) are looking thus increasing the frame rate.