Hardware accelerated rendering of foliage for real-time applications

Abstract

One of the major challenges in developing techniques for realistic and high performance visualization of outdoor environments is rendering of vegetation. The greatest problem is that convincing modeling of trees, bushes and undergrowth requires very large numbers of polygons that exceed the limits posed by rendering hardware today (and in the near future). A number of methods have been proposed in the past to address the issue, most of which are variants of multi-resolution modeling and level-ofdetail algorithms. This paper reviews some of the landmark techniques used in real-time PC applications (mostly games and flight-simulators), and presents a solution that takes advantage of the programmable rendering pipelines available on most of the recent video cards. The algorithm uses view dependent 2.5 dimensional impostors to visualize trees in convincing quality for most levels of detail. Numeric results are presented to illustrate rendering efficiency, and specific, implementation related issues are also discussed.