一种基于环境映照变换的快速光线跟踪算法

A QUICK RAYTRACING ALGORITHM BASED ON THE TRANSFORMATION OF THE ENVIRONMENT MAP

环境映照是简化光线跟踪过程、增强画面真实感的有效方法之一．现有的环境映照技术不能精确地生成物体表面的镜面反射分量和折射分量，只能大致反映周围环境对物体表面光亮度的影响．本文提出的基于环境映照变换的光线跟踪算法是在原有的环境映照上增加了景物可见点的深度信息，只需对相邻环境映照立方体表面上少量象素内所记录的可见点作再投影就能求得各光线入射点处精确的镜面反射分量和折射分量．这个算法完全是在图像空间解决问题，与场景的复杂程度无关．本方法为实时生成镜面反射效果和折射效果提供了一条很有潜力的实现途径．

Raytracing is one of the main method to synthesis the photorealistic image, but the largeamount of computation limits the application of this algorithm. The development of virtual realityrequires high ability of real-time rendering algorithm. Environment mapping can not generate thereflection and the refraction intensity exactly. This paper proposed a quick raytracing algorithmbased on the transformation of the environment map. This method adds depth information in theenvironment map and generates the exact reflection and refraction intensity with the transformation ofa few pixels. The rendering time is proportional to the environment map resolutions and isindependent of the scene complexity.