火焰动画在影视、动漫、游戏等领域有着广泛的应用,而逼真模拟细节丰富的多形态火焰动画一直是图形学研究领域的难点.以Level-Set曲面变形为基础,提出了将目标形态、路径约束和燃烧传播相结合的火焰蓝芯曲面演化模型,以此模拟沿路径的火焰蔓延、移动燃烧物等现象.并针对目前模拟中火焰细节不足的问题,引入修正的MacCormack高阶对流求解器;同时,采用烟密度演化曲线模拟燃烧过程中的烟雾生成,进一步提高火焰真实感.实验结果表明该方法能逼真模拟沿路径的火焰蔓延、移动燃烧物以及其他多形态且细节丰富的火焰动画.
Fire animation is very attractive to artists and now widely used in many fields,such as film making,cartoons,computer games,fire prevention,visual reality.In the field of computer graphics,however,it has been a difficult issue to realistically simulate various flame effects with rich details.This paper presents an evolution model based on Level-Set metamorphosis and uses the combination of target shape,path constraint,and combustion propagation to evolve the blue core of fire,so as to simulate the path-based flame spreading,mobile-burning objects,etc.In addition,aiming to address the lack of flame details in current fire simulation,we use the modified MacCormack which is a high-order advect solver to lower numerical dissipation and enhance the solution precision of our fire model.Moreover,to further improve the realism of the fire animation,a curve of smoke density evolution is adopted to sculpt the soot production during the burning process.In this way,we can render flame and soot together to obtain a more realistic vision effect.Experimental results show that the proposed method is able to conduct realistic simulation of path-based flame propagation,mobile-burning objects,and other various fire animations with rich details.