Multi-Scale Stochastic Modelling of Complex Natural Phenomena

AbstractNo abstract, here’s the motivation from the paper.The appearance of natural phenomena has always intrigued humankindu0002 This fascination isevident from the vast array of depictions of natural phenomena createdu0012 ranging from earlycave paintings to impressionistic masterworksu0002 With the advent of photography and u000elmu0012many aspects of natural phenomena can be depicted by a semiautomatic procedureu0002 Thereareu0012 howeveru0012 many reasons why such depictions are not always satisfyingu0002 Movies requirespecial efects not commonly found in nature or which occur only very rarelyu0002 Alsou0012 evenif the real phenomenon can be foundu0012 controlling it can be a diu0015cult and even dangeroustasku0002 It is necessaryu0012 thenu0012 to artiu000ecially create phenomena such as explosions for entertainmentu0002 In response to the need to evoke and control natureu0012 scientists have proposed manydescriptive physical models of natural phenomenau0002 Although scientists share the same fascination of nature as artistsu0012 scientists need to command or predict the behaviour of certainphenomenau0002 Hereu0012 physical models can be used to simulate the phenomenon on a computeru0002In factu0012 a visual simulation of the phenomenon is obtained when the data of a simulationis mapped into a visual depictionu0002 The simulation itselfu0012 howeveru0012 is not necessarily basedon a physical modelu0002 In the context of this thesisu0012 both a cartoon and a visualization of aphysical simulation are referred to as visual simulationsu0002The visual simulation of virtual environments has many practical applicationsu0002 In addition to art and entertainment these include u0014ight simulation and scientiu000ec visualizationu0002Natural phenomena such as smokeu0012 cloudsu0012 grass and hairu0012 are ubiquitousu0002 It is thereforeimportant to design convincing visual simulations for themu0002 For exampleu0012 in u0014ight simulatorsu0012 it is critical that clouds and terrain be carefully depicted because they serve as vitalvisual cues to a pilotu0002 Howeveru0012 this is not the only constraint imposed on a simulationu0002 Inthe entertainment industryu0012 it is fundamental to be able to choreograph certain phenomenain order to create a desired moodu0002 The simulation of natural phenomena in the contextof computer graphics is therefore subjected to two constraintsu001e visual consistency and usercontrolu0002 Finding an optimal compromise between these two constraints for some classes ofnatural phenomena is the goal of this thesisu0002