湿地场景的实时动态模拟

Real-Time Simulation of Dynamic Wetland Scenes

实现了一个湿地场景的实时模拟系统,能实时模拟包含数万棵树、数十万棵草,以及自然地形、水面等丰富景观元素的动态湿地场景.为增强场景真实感,提出一种基于环境遮挡的光照算法,以改进几何-图像混合式树木模型的绘制效果;还提出一些高效率的方法近似模拟水面的折射、反射等光学现象,以及晴天、雨天等各种天气条件下的光照效果.在动态模拟方面,结合预计算的关节式形变以及过程式动画2种方法,模拟了树木及花草的随风摇曳效果;还模拟了湖面的微波以及雨天的雨线效果及在水面形成的涟漪.为了提高模拟效率,采用了多种细节层次技术以及最新的GPU加速技术.

This paper presents a platform for real-time simulation of wetlands. It enables efficient modeling and rendering of large-scale natural wetlands composed of rich scene elements, e. g. , tens of thousands of trees, hundreds of thousands of grass blades, natural terrain and lakes. In order to enhance the scene reality, we propose several simple yet effective algorithms to simulate the shading effects of the trees with the hybrid geometry/image representation, the refraction and reflection effects of the water surface and the lighting effects under various weather conditions. The swaying movements of trees and grasses are synthesized by incorporating pre-computed joint-based deformation of plants with procedural animation. The microwaves of lakes, the rain strokes and water ripples in rainy days are also simulated. Our system achieves interactive rendering frame rates by applying level-of-detail techniques in various aspects and taking full advantages of the newest GPU acceleration features.