In the pre-process, we transform the complex HDR environment map and the measured BRDF data into the scattered SRBF representation by using the non-uniform and non-negative SRBF fitting algorithm.

• 在前处理时，我们透过非线性最佳化的演算法，将高动态范围环境光源贴图以及双向反射分布函数转换成球面辐射基底函数的表示形式。