地球外层空间物体真实感成像建模与绘制研究

Research on Modeling and Rendering of Realistic Imaging for Object in Spatial Space

针对现有模型在地球外层空间物体真实感成像绘制中的局限性和不足,建立一种基于几何光学原理和光线追踪技术的BRDF微面元模型.该模型综合了微面元的朝向分布和表面反射率以及微面元之间遮挡关系对地球外层空间物体表面反射特性影响,以提高对空间物体表面反射光空间分布特征的建模精度,并把光学反射特性分解为微面元的漫反射特性和镜面反射特性两个分量,不仅能反映空间物体整体亮度特征,而且能描述空间物体局部高光特征.通过与实际测量数据比较,该模型曲线与测量结果基本一致.实验结果表明,采用该模型能够实现对地球外层空间物体真实感成像绘制效果.

A new model about BRDF defined by microfacet was developed for spatial object optical reflection modeling based on the principle of optical geometry and the technique of ray tracing.This model briefly contains the contribution to spatial object reflection characteristics by the microfacet normal direction,reflectivity and the shelter relation among microfacets.The diffuse reflection and the mirroring reflection are employed by this model in order to calculate the whole luminance characteristic and the local high luminance characteristic of spatial object.The result of validating work showed that the BRDF microfacet model curve is basically consistent as the actual measurement data curve.The rendering experiment expressly proved that the BRDF microfacet model could be used to simulate the effect exactly and calculate the optical reflection characteristic accurately of spatial object.