基于锥形射线族投射的非直接光照算法

Indirect Illumination Algorithm Based on Cone-rays Cast

在可交互应用中,基于射线投射的非直接光照采样数目常常受限。为此,考虑到空间关联,提出使用锥形射线族进行投射求交的算法,利用锥形边界预排除场景元素,并使用无堆栈算法在GPU中完成非直接光照计算,同时对算法使用的数据存储区域进行优化以达到更好的访问带宽,通过OpenCL和OpenGL实现该算法,结果证明该算法可以有效地计算非直接光照,相对于射线投射算法平均有2倍左右的性能提升。

The indirect lighting calculations based on the ray-cast is a time-consuming process, therefore, the number of samples is limited in interactive program. Considered of spatial correlation, cone-ray cast algorithm is proposed to alleviate insufficient samples. It employs conical boundary to pre-exclude scene＇s elements, and implements in GPU as stack-less algorithm, additionally, optimizes storage location of the data to achieve the wider bandwidth, which is implemented by employ OpenGL and OpenCL. The result shows that the algorithm can efficiently compute indirect illumination, and brings about two-fold performance increase.