基于物理特性的雾效仿真方法  

Simulation method of fog effect based on physical properties

作　　者：曹旭 季玉龙[3] 

机构地区：[1]四川大学计算机学院,成都610065 [2]四川大学视觉合成图形图像技术国家重点学科实验室,成都610065 [3]四川大学空天科学与工程学院,成都610065

出　　处：《计算机应用》2017年第A02期190-192,202,共4页journal of Computer Applications

基　　金：国家863计划项目(2015AA016404-3);中央高校基本科研业务费资助项目(2015SCU102)

摘　　要：针对传统雾效仿真方法模拟出的烟雾真实感较差且难以满足实时性要求的问题,提出了一种基于物理特性的雾效仿真方法。采用经典力学模型N-S(Naiver-Stokes)方程来描述烟雾的运动,并考虑周围环境的影响,引入风力作用提高烟雾运动的真实性。首先,建立风场模型,运用线性滤波法(自回归(AR)法)求解参数得到风速时程,减少了计算量且模拟速度快;然后,使用分步求解法对引入风力项的方程进行简化处理,求解过程中采用半拉格朗日法求解平流项,实现方程的快速求解;最后,利用漩涡约束技术恢复烟雾表面的湍流效果,并考虑重力、热浮力的作用来增强烟雾的运动细节。实验结果表明,所提方法满足实时系统对渲染帧率的要求,并能够模拟出自然动态的平流雾效果。Focused on the issue that traditional fog simulation methods are hard to be competent for the smoke simulation with high requirement of realness and real-time,a fog simulation method based on physical properties was proposed, which used the classical mechanical model Naiver-Stokes（ N-S） equation to describe the movement of smoke, with the influence of the environment considered, the wind effect was adopted to improve the realness of fog. Firstly, the wind field model was established, and linear filtering method（ Auto-Regression（ AR） method） was used to solve the parameters of the wind speed time series to reduce the computation time and ensure fast simulation. Secondly, using the decomposition method to simplify the solution process of equations, the semi-Lagrange method was adopted to solve the advection item. Finally, the vortex confinement technique was introduced to recover the turbulence effect,in order to enhance the details of the fog movement, the effect of gravity and thermal buoyancy was also considered. The experimental results show that the proposed method can generate realistic fog in real-time.

关 键 词：N-S方程 线性滤波法 雾效渲染 脉动风 平流雾 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]