基于二分内包围盒的玉米光照逆光线跟踪算法

Inverse ray tracing algorithm based on bipartite inner bounding box for illumination of maize

为了在玉米仿真中构建逼真有效的光环境,提出一种基于二分内包围盒的玉米光照逆光线跟踪算法。在玉米表面建立二分内包围盒进行预处理,减少光线与玉米相交运算量;引入遮挡因子简化光能计算的复杂度;通过调整光能阈值达到光环境逼真度和算法效率的统一。为了验证算法的快速有效性,建立玉米模型,对比不同包围盒求交运算的速率,得出二分内包围盒的求交速度最快,逆光线跟踪算法模拟出的玉米生长效果较为逼真。

To construct a realistic and effective light environment,this paper proposed an inverse ray tracing algorithm based on bipartite inner bounding box for illumination of maize.Firstly,as a pre-process,this paper constructed the bipartite inner bounding box on the surface of the maize,which could reduce the intersection calculations between rays and maize.Secondly,this paper introduced occlusion coefficient to simplify the complexity of calculation of light energy.Finally,on the basis of adjusting the light energy threshold,this paper achieved the organic unity of the fidelity of light environment and algorithm efficiency.In order to validate the efficiency of the algorithm,it established the 3D maize model and compare these rates of diffe- rent bounding box intersection operations.The results show that the rate of intersection operation of bipartite inner bounding box is the fastest,and the growth effect of maize simulated by inverse ray tracing algorithm is more realistic.