气象数据驱动的三维云增强绘制方法  

3D Cloud Enhancement Rendering Method Driven by Meteorological Data

作　　者：秦绪佳[1] 赵铮 柯玲玲 郑红波[1] 马骥 QIN Xu-jia;ZHAO Zheng;KE Ling-ling;ZHENG Hong-bo;MA Ji(School of Computer Science and Technology,Zhejiang University of Technology,Hangzhou 310032,China)

机构地区：[1]浙江工业大学计算机科学与技术学院,杭州310032

出　　处：《小型微型计算机系统》2021年第6期1297-1303,共7页Journal of Chinese Computer Systems

基　　金：国家自然科学基金项目(61702455,61672462,61902350)资助;浙江省自然科学基金项目(LY20F020025)资助.

摘　　要：基于气象数据直接体绘制的方法对三维云进行可视化时,如果使用低精度、少层级的网格数据就会造成模拟数据在垂直方向上相对稀少,从而导致云面会十分粗糙、渲染效果缺乏真实性.为了解决这个问题,本文提出一种利用纹理噪声引入随机抖动从而使云面细节丰富、有较强真实感的方法.首先生成3D Perlin噪声纹理并采样,再和气象数据的原始纹理以不同的比例进行融合.该方法可以让三维云整体有更好的立体感以及更佳的视觉感受.此外,仅仅用数值模拟绘制云虽然已经模拟了光的反射和吸收,但并未涉及到光的散射效应,所以使用数值模拟绘制出来的云真实感仍旧不够.为了绘制出更具有真实感的三维云,本文结合Cook Torrance光照模型和双向反射分布函数(BRDF)对传统光照模型进行改进.此改进模型考虑了材质微平面对光照的影响,运用到对三维云的可视化中,可以得到真实感较强的三维云仿真效果.When 3D cloud is visualized based on the method of direct volume rendering of meteorological data,if the grid data with low accuracy and few levels is used,the simulation data will be relatively rare in the vertical direction,resulting in very rough cloud surface and lack of authenticity in rendering effect.In order to solve this problem,this paper proposes a method to introduce random jitter into the texture noise so as to make the cloud surface more detailed and realistic.Firstly,3D Perlin noise texture is generated and sampled,and then fused with the original texture of meteorological data in different proportions.This method can make the three-dimensional cloud as a whole have better stereoscopic sense and better visual perception.In addition,although the reflection and absorption of light have been simulated by using numerical simulation to draw clouds,the scattering effect of light has not been involved,so the sense of reality of clouds drawn by numerical simulation is still insufficient.In order to draw a more realistic 3D cloud,this paper combined Cook Torrance lighting model and bidirectional reflection distribution function(BRDF)to improve the traditional lighting model.This improved model takes the effect of material microplane on illumination into consideration,and when applied to the visualization of 3D cloud,the 3D cloud simulation effect with strong sense of reality can be obtained.

关 键 词：三维云仿真 体绘制 随机扰动 COOK Torrance光照模型 双向反射分布函数 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]