A practical analytic single scattering model for real time rendering
A practical analytic single scattering model for real time rendering
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DOI：
10.1145/1186822.1073309
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发表时间：
2005-07
期刊：
影响因子：
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通讯作者：
Bo Sun;R. Ramamoorthi;S. Narasimhan;S. Nayar
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文献类型：
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作者：
Bo Sun;R. Ramamoorthi;S. Narasimhan;S. Nayar
我们考虑在参与媒体中实时渲染场景，捕捉雾，薄雾和阴霾中的光散射效果。虽然已经开发了一些基于蒙特卡罗和有限元模拟的复杂方法，但这些方法在交互速率下不起作用。最常见的实时方法基本上是OpenGL雾模型的简单变体。虽然易于使用和指定，但该模型排除了许多重要的定性效果，如光源周围的辉光、体积散射对表面外观的影响（如光泽高光的漫射）以及复杂照明下的外观（如环境贴图）。在本文中，我们提出了一种替代的基于物理的方法，捕捉这些效果，同时保持真实的时间性能和易用性的OpenGL雾模型。我们的方法是基于一个显式的解析积分的单散射光传输方程的各向同性点光源在均匀的参与介质。我们可以使用一些存储为纹理映射的小型数字查找表在现代可编程图形硬件中实现该模型。我们的模型也可以很容易地适应生成任意BRDF，环境地图照明和预先计算的辐射传输方法，在参与媒体的存在下，材料的外观。因此，我们的技术可以广泛应用于实时渲染。
We consider real-time rendering of scenes in participating media, capturing the effects of light scattering in fog, mist and haze. While a number of sophisticated approaches based on Monte Carlo and finite element simulation have been developed, those methods do not work at interactive rates. The most common real-time methods are essentially simple variants of the OpenGL fog model. While easy to use and specify, that model excludes many important qualitative effects like glows around light sources, the impact of volumetric scattering on the appearance of surfaces such as the diffusing of glossy highlights, and the appearance under complex lighting such as environment maps. In this paper, we present an alternative physically based approach that captures these effects while maintaining real time performance and the ease-of-use of the OpenGL fog model. Our method is based on an explicit analytic integration of the single scattering light transport equations for an isotropic point light source in a homogeneous participating medium. We can implement the model in modern programmable graphics hardware using a few small numerical lookup tables stored as texture maps. Our model can also be easily adapted to generate the appearances of materials with arbitrary BRDFs, environment map lighting, and precomputed radiance transfer methods, in the presence of participating media. Hence, our techniques can be widely used in real-time rendering.