植物冠层光照的建模与虚拟现实仿真研究

Approach of Modeling and VR-based Simulation for Plant Canopy Lighting

植物虚拟现实仿真是将植物看作一个器官集合,从功能和几何结构上描述植物体(群落),并利用计算机相关技术进行三维可视化的研究工作。绝大多数的植物生长过程主要由光照驱动,所以植物虚拟现实仿真研究工作中对器官吸收光照的测量十分重要。首先根据光照与植物冠层的作用关系,给出了适用于PAR或UV下植物生长过程模拟中器官截取太阳光线和天空光线的辐亮度公式;通过光线投射和投影方法分析了主光源对植被冠层照射的作用原理;结合Monte Carlo光线追踪方法和辐射度方法总结了植物冠层的光线多重散射描述方法;最后利用虚拟现实建模语言对植物冠层光照及环境进行三维可视化模拟和输出。图6,表3,参25。

VR - based simulation of plant studies functionally and geometrically plants as sets of interconnected organs. As many plant processes are driven by light, it is the key for virtual plant to estimate the light absorbed by each organ. This has motivated the develop- ment of dedicated light models taking about profit from the 3D geometry provided by virtual plant models. Presents the radiance equa- tion that suitable for calculating sun and sky light intercepted by plant organs based on the principles of the interactions between light and plant canopy firstly ; such methods can be used for the simulation of process depending on the UV or PAR radiations ; analyses the process principles of plant canopy primary lighting based on ray casting and projection secondly ; concludes the descriptions taking into account the multiple scattering of plant lighting based on Monte Carlo ray tracing method and on the radiosity method thirdly ; and con- firms the research with 3D visualization based on Virtual Reality Modeling Language （VRML） finally.