Efficient simulation of light transport in scenes with participating media using photon maps
Efficient simulation of light transport in scenes with participating media using photon maps
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DOI：
10.1145/280814.280925
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发表时间：
1998-07
期刊：
影响因子：
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通讯作者：
H. Jensen;Per H. Christensen
中科院分区：
文献类型：
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作者：
H. Jensen;Per H. Christensen
本文提出了一种计算具有参与媒体的场景中的全局照明的新方法。该方法基于双向蒙特卡罗射线追踪，并使用光子图来提高效率并降低噪声。我们通过引入包含参与介质中光子的体积光子图，消除了先前将光子图方法限制于表面的限制。我们还得出了体积光子图中光子的新辐射率估计。该方法快速、简单，而且通用性足以处理非均匀介质和各向异性散射。它可以有效地模拟多种效果，例如多重体积散射、体积和表面之间的渗色以及体积焦散（从镜面表面反射或透射的光，然后由介质散射）。光子贴图与场景的几何表示解耦，使得该方法能够模拟包含复杂对象的场景中的全局照明。这些对象不需要进行细分；它们可以被实例化，甚至可以由隐式函数表示。由于该方法基于双向模拟，因此它会自动适应照明和视图。此外，由于光子贴图的使用减少了噪声和锯齿，因此该方法适合动画的渲染。
This paper presents a new method for computing global illumination in scenes with participating media. The method is based on bidirectional Monte Carlo ray tracing and uses photon maps to increase efficiency and reduce noise. We remove previous restrictions limiting the photon map method to surfaces by introducing a volume photon map containing photons in participating media. We also derive a new radiance estimate for photons in the volume photon map. The method is fast and simple, but also general enough to handle nonhomogeneous media and anisotropic scattering. It can efficiently simulate effects such as multiple volume scattering, color bleeding between volumes and surfaces, and volume caustics (light reflected from or transmitted through specular surfaces and then scattered by a medium). The photon map is decoupled from the geometric representation of the scene, making the method capable of simulating global illumination in scenes containing complex objects. These objects do not need to be tessellated; they can be instanced, or even represented by an implicit function. Since the method is based on a bidirectional simulation, it automatically adapts to illumination and view. Furthermore, because the use of photon maps reduces noise and aliasing, the method is suitable for rendering of animations.