Future Trends in Computer Graphics： How Much is Enough？

Over the forty-year history of interactive computer graphics, there have beencontinuous advances, but at some stage this progression must terminate with images beingsufficiently realistic for all practical purposes. How much detail do we really need? Polygon countsover a few million imply that on average each polygon paints less than a single pixel, making useof polygon shading hardware wasteful. We consider the problem of determining how much realism isrequired for a variety of applications. We discuss how current trends in computer graphics hardware,and in particular of graphics cards targeted at the computer games industry, will help or hinderachievement of these requirements. With images now being so convincingly realistic in many cases,critical faculties are often suspended and the images are accepted as correct and truthful althoughthey may well be incorrect and sometimes misleading or untruthful. Display resolution has remainedlargely constant in spatial terms for the last twenty years and in terms of the number of pixels hasincreased by less than an order of magnitude. If the long-promised breakthroughs in displaytechnology are finally realised, how should we use the increased resolution?

Three-dimensional trees for virtual globes

One of the problems in virtual globes technologies is the real-time representation of vegetal species.In forest or garden representations,the low detailed plants produce a lack of realism.Efficient techniques are required to achieve accurate interactive visualisation due to the great number of polygons the vegetal species have.This article presents a multi-resolution model based on a geometric representation of vegetal species that allows the application to perform the progressive transmission of the model,that is,the transmission of a simple representation followed by successive refinements of it.It has a hardware-oriented design in order to obtain interactive frame rates.The geometric data of the objects are stored in the graphics processing unit and,moreover,the change from one approximation to another is obtained by performing mathematical calcula-tions in this graphics hardware.The multi-resolution model presented here enables instancing:as many vegetal species as desired can be rendered with different levels of detail,while all of them are accessing the same geometric data.This model has been used to build a real-time representation of a not imaginary scenario.

Z^2 traversal order: An interleaving approach for VR stereo rendering on tile-based GPUs

With increasing demands of virtual reality(VR) applications, efficient VR rendering techniques are becoming essential. Because VR stereo rendering has increased computational costs to separately render views for the left and right eyes, to reduce the rendering cost in VR applications, we present a novel traversal order for tile-based mobile GPU architectures: Z^2 traversal order. In tile-based mobile GPU architectures,a tile traversal order that maximizes spatial locality can increase GPU cache efficiency. For VR applications, our approach improves upon the traditional Z order curve.We render corresponding screen tiles in left and right views in turn, or simultaneously, and as a result, we can exploit spatial adjacency of the two tiles. To evaluate our approach, we conducted a trace-driven hardware simulation using Mesa and a hardware simulator. Our experimental results show that Z^2 traversal order can reduce external memory bandwidth requirements and increase rendering performance.