基于BRDF 和GPU 并行计算的全局光照实时渲染

基于光线追踪，将屏幕图像像素分解为投射光线与场景对象交点面片辐射亮度和纹理贴图的合成，每个面片的辐射亮度计算基于双向反射分布函数(BRDF)基的线性组合，并通过图形处理器(GPU)处理核心并行绘制进行加速，最后与并行计算的纹理映射结果进行合成。提出了一种基于BRDF 和GPU 并行计算的全局光照实时渲染算法，利用GPU 并行加速，在提高绘制效率的前提下，实现动态交互材质的全局光照实时渲染。重点研究：对象表面对光线的多次反射用BRDF 基的线性组合来表示，将非线性问题转换为线性问题，从而提高绘制效率；利用GPU 并行加速，分别计算对象表面光辐射能量和纹理映射及其线性组合，进一步提高计算效率满足实时绘制需求。

Global Illumination Real-Time Rendering Based on BRDF and#br#GPU Parallel Computing

While raytracing, the screen image pixel is decomposed into the combination of radianceand texture of the patches, created as scene objects intersect with the casting ray. The radiance of eachpatch is calculated at the linear combination of the bases of bi-directional reflectance distributionfunction (BRDF), and able to be accelerated by graphics processing unit (GPU) parallel rendering.This paper presents a global illumination rendering algorithm based on BRDF and GPU parallelcomputation. With GPU parallel acceleration, through improving the efficiency of rendering, thealgorithm achieves global illumination real-time rendering of the scene including dynamic interactivematerial. The key research: object surface’s multiple reflection characteristic is represented by linearcombination of the basis of BRDF, so transforming the nonlinear problem to a linear one, thusimprove the rendering efficiency. With GPU parallel acceleration, the algorithm calculates the objectsurface’s radiation energy and texture mapping and their linear combination, further improving theefficiency of rendering to meet the requirement of real-time.