基于可视区域间接光照聚类的虚拟点光源采样

Virtual-Point-Light Sampling Algorithm Based on Indirect Illumination Clustering of Visible Scene Region

针对间接光照计算精度问题,提出改进的可视区域敏感的虚拟点光源采样方法。设计依据可视场景点位置及其法向量对可视场景点进行聚类的方法;计算虚拟点光源对各类中心位置对应可视场景点的光照贡献与类中可视场景点个数之积的累加和,并把累加和作为该虚拟点光源对可视区域的间接光照贡献估计值;以此估计值构造累积概率分布函数,据此选取实际计算每个可视场景点间接光照时所用的虚拟点光源。实验结果表明,该方法能够以较少虚拟点光源实现真实感强的间接光照效果绘制,提高间接光照计算精度。

Focusing on the accuracy of indirect illumination calculation,an improved view-sensitive virtual point light(VPL)sampling method is proposed.The visible shading points are clustered according to the positions and normal vectors.The product of the contribution of VPLs on the representative visible shading points and the number of VPLs belonging to the same class is calculated,and the sum of the products is treated as the estimation of the indirect illumination which constructs the cumulative distribution function(CDF).On the basis of the CDF,the VPLs of calculating the indirect illumination on every visible shading point are selected.Experiment results show that the proposed algorithm can achieve better indirect lighting effect with fewer VPLs,and improve the accuracy of indirect illumination calculation.