基于高级渲染器Renderman的水流材质系统的研究与设计
摘要
随着计算机硬件和多媒体技术的发展,计算机三维动画的应用领域和应用程度在不断提高,在军事仿真、建筑景观设计、虚拟现实、医疗卫生、娱乐和教育等众多领域得到广泛的应用。
在三维动画制作过程中,材质(shader)是视性属性的综合体现,是表现视觉艺术效果的关键之一。但是主流计算机三维动画软件,例如Maya、3dmax等存在着局限性,这主要是由于它们大众软件缺乏针对性特性决定的,例如渲染速度局限性和没有针对专门动画片特别设计,三维模型表面的材质种类单一,可交互性差,可控参数的数量和种类少,因此,在第三方渲染器中设计新的材质以提高渲染速度和效益有很重要的意义。
Renderman是一款在好莱坞的动画片中广泛应用,技术成熟并提供接口扩展的一流渲染器。本文通过对Renderman的Rsl(Renderman Shading Lanuage)技术研究,结合物理学、图形学、数学和计算机编程等多个领域的研究,设计一个基于Renderman的包含海水、湖水、溪水和泳池水的水流材质系统。该系统结合Maya等三维设计软件应用于三维动画制作,有很广阔的应用前景。
论文详细介绍了该系统的设计方案与各子模块的开发过程,包括海水模块、湖水模块、溪水模块和泳池水模块。各个模块都采用软件技术实现,采用Rsl、随机过程理论和图形学等技术,在硬件方面要求低,不需要对现有的硬件多任何的投资。因此,系统成本低、速度快。根据该设计方案,本论文完成了该系统的开发工作,实现了包含海水、湖水、溪水和泳池水的水流材质系统。试验证明有良好的速度和视觉效果。
With the development of computer hardware and multimedia technology, computer 3D cartoon becomes widely used in battlefield simulatio, landscaping, visual reality, medical and sanitation, entertainment and education etc.
During implementing the three-dimensional cartoons, shaders are one of the important keys in artistic effect. But for the localization which determinated for its polulation such as render speed and no customization for special project, the kind of the shaders for the 3D model are poor, and low interactive capability in the main software such as Maya or 3dmax. Therefore, it is important to update the render speed and benefit when design new shader system in the third-party renders.
Renderman is a rendering software used widely in Hollywood with its advantages as bellows: affording interface extension, having mature technology. The paper designed a stream shader system including sea water module、lake water module、brook water module and natatorium water module in Renderman based on the research in Rsl techonolgy combined with physics、computer graphics、maths、aesthetics、computer programming. The system has broad application foreground when combined with 3D software such as Maya in designing 3D cartoon.
The design of the system and the realization of modules including sea water module、lake water module、brook water module and natatorium water module that were depicted in this paper. All of the modules are accomplished by software technology with using Rsl, stochastic process theory and computer graphics.Because of the little investment on hardware, the system has the virtue of low cost, high render speed. According to the design scheme of the project, the development work and the function of sea water module, lake water module, brook water module and natatorium water module were finished. Through experiment, the results indicate that the system archives good perceptual picture quality and favorable speed.
在三维动画制作过程中,材质(shader)是视性属性的综合体现,是表现视觉艺术效果的关键之一。但是主流计算机三维动画软件,例如Maya、3dmax等存在着局限性,这主要是由于它们大众软件缺乏针对性特性决定的,例如渲染速度局限性和没有针对专门动画片特别设计,三维模型表面的材质种类单一,可交互性差,可控参数的数量和种类少,因此,在第三方渲染器中设计新的材质以提高渲染速度和效益有很重要的意义。
Renderman是一款在好莱坞的动画片中广泛应用,技术成熟并提供接口扩展的一流渲染器。本文通过对Renderman的Rsl(Renderman Shading Lanuage)技术研究,结合物理学、图形学、数学和计算机编程等多个领域的研究,设计一个基于Renderman的包含海水、湖水、溪水和泳池水的水流材质系统。该系统结合Maya等三维设计软件应用于三维动画制作,有很广阔的应用前景。
论文详细介绍了该系统的设计方案与各子模块的开发过程,包括海水模块、湖水模块、溪水模块和泳池水模块。各个模块都采用软件技术实现,采用Rsl、随机过程理论和图形学等技术,在硬件方面要求低,不需要对现有的硬件多任何的投资。因此,系统成本低、速度快。根据该设计方案,本论文完成了该系统的开发工作,实现了包含海水、湖水、溪水和泳池水的水流材质系统。试验证明有良好的速度和视觉效果。
With the development of computer hardware and multimedia technology, computer 3D cartoon becomes widely used in battlefield simulatio, landscaping, visual reality, medical and sanitation, entertainment and education etc.
During implementing the three-dimensional cartoons, shaders are one of the important keys in artistic effect. But for the localization which determinated for its polulation such as render speed and no customization for special project, the kind of the shaders for the 3D model are poor, and low interactive capability in the main software such as Maya or 3dmax. Therefore, it is important to update the render speed and benefit when design new shader system in the third-party renders.
Renderman is a rendering software used widely in Hollywood with its advantages as bellows: affording interface extension, having mature technology. The paper designed a stream shader system including sea water module、lake water module、brook water module and natatorium water module in Renderman based on the research in Rsl techonolgy combined with physics、computer graphics、maths、aesthetics、computer programming. The system has broad application foreground when combined with 3D software such as Maya in designing 3D cartoon.
The design of the system and the realization of modules including sea water module、lake water module、brook water module and natatorium water module that were depicted in this paper. All of the modules are accomplished by software technology with using Rsl, stochastic process theory and computer graphics.Because of the little investment on hardware, the system has the virtue of low cost, high render speed. According to the design scheme of the project, the development work and the function of sea water module, lake water module, brook water module and natatorium water module were finished. Through experiment, the results indicate that the system archives good perceptual picture quality and favorable speed.
引文
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[5]Michael Kass,Gavin Miller.Rapid,Stable Fluid Dynamics for Computer Graphics.Compter Graphics,1990,24(4):49-57.
[6]Nick Forester,Ronald Fedkiw.Practical Animation of Liquids.Proceedings of the 28th annual conference on Computer graphics and interactive techniques,2001:23-30.
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[14]王永强.RenderMan中RIB文件的研究及其改进[J].微型电脑应用.2005年21卷第7期.
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[16]Anthony A.Apodaca Larry Gritz.Advaned Renderman-Creating CGI for Motion Pictures[M].2000年.
[17]王永强.RenderMan中RIB文件的研究及其改进[J].微型电脑应用.2005年21 卷第7期.
[18]E.Monahan and G.MacNiocaill,editors.Oceanic Whitecaps:TheirRoleinAirSea Exchange Processes.D.Reidel,1986.
[19]徐彬.海洋波浪的动态可视化研究与实现[硕士学位论文].中国海洋大学.2006年.
[20]皱欣昂.动态场景的全局光照实时绘制:[硕士学位论文].湖南:湖南大学.
[21]孙传东,陈良益,高立民,张建生,卢笛.水的光学特性及其对水下成像的影响[J].应用光学.2000年第4期.
[22]彭东,陈尚品,吴树通,曹俊.关于瑞利散射在九寨沟、黄龙水体颜色形成中作用的讨论[J].四川地质学报.2006年3月第26卷.
[23]张闻芳.自然景物的三维表现方法研究[硕士学位论文].湖南:湖南大学.2007年.
[24]彭群生,梁有栋.真实感图形的计算机生成[J].计算机学报.1989年.
[25]宫 文,樊养余,张胜超,李胜亮.一种基于光线跟踪的软阴影算法[J].计算机工程与应用.2008年44期.
[26]Scott Iverson.Air[M].2001年.
[2]Perlin K.An image synthesizer.Computer Graphics,1985,19(3):287-296.
[3]Peachey D R.Modeling waves and surf.Computer Graphics,1986,20(4):65-74
[4]Fourier A.A simple model of ocean waves.Computer Graphics,1986,20(4):75-83.
[5]Michael Kass,Gavin Miller.Rapid,Stable Fluid Dynamics for Computer Graphics.Compter Graphics,1990,24(4):49-57.
[6]Nick Forester,Ronald Fedkiw.Practical Animation of Liquids.Proceedings of the 28th annual conference on Computer graphics and interactive techniques,2001:23-30.
[7]童若锋,汪国昭.用于动画的水波造型[J].计算机学报,1996.
[8]张尚弘,陈垒,赵登峰,王兴奎.基于粒子系统的流场实时模拟[J].水利水电技术.
[9]常志伟.基于与粒子系统实现喷泉效果[硕士学位论文]:郑州:郑州大学.2007年.
[10]Reeves W T,Ricki Blau.Approximate and Probabilistic Algorithms for shading and Rendering Structured Particle Systerms.1985:19(3)313-321.
[11]Ian Stephenson.Essential Renderman Fast[M].Springer,2003.
[12]Anthony A.Apodaca,Larry Gritz.Advanced Renderman2-To RIINFINITYand Beyond[M].San Francisco:Morgan Kaufmann Publishers,2000.
[13]王子健.RAT使用情况和使用方法[J].技术与艺术.2005年.
[14]王永强.RenderMan中RIB文件的研究及其改进[J].微型电脑应用.2005年21卷第7期.
[15]徐鸿,陈福民.基于RenderMan渲染平台的毛发系统的改进[J].计算机应用与软件.2004年11月21卷第11期.
[16]Anthony A.Apodaca Larry Gritz.Advaned Renderman-Creating CGI for Motion Pictures[M].2000年.
[17]王永强.RenderMan中RIB文件的研究及其改进[J].微型电脑应用.2005年21 卷第7期.
[18]E.Monahan and G.MacNiocaill,editors.Oceanic Whitecaps:TheirRoleinAirSea Exchange Processes.D.Reidel,1986.
[19]徐彬.海洋波浪的动态可视化研究与实现[硕士学位论文].中国海洋大学.2006年.
[20]皱欣昂.动态场景的全局光照实时绘制:[硕士学位论文].湖南:湖南大学.
[21]孙传东,陈良益,高立民,张建生,卢笛.水的光学特性及其对水下成像的影响[J].应用光学.2000年第4期.
[22]彭东,陈尚品,吴树通,曹俊.关于瑞利散射在九寨沟、黄龙水体颜色形成中作用的讨论[J].四川地质学报.2006年3月第26卷.
[23]张闻芳.自然景物的三维表现方法研究[硕士学位论文].湖南:湖南大学.2007年.
[24]彭群生,梁有栋.真实感图形的计算机生成[J].计算机学报.1989年.
[25]宫 文,樊养余,张胜超,李胜亮.一种基于光线跟踪的软阴影算法[J].计算机工程与应用.2008年44期.
[26]Scott Iverson.Air[M].2001年.