Photon Beam Diffusion: A Hybrid Monte Carlo Method for Subsurface Scattering|
Ralf Habel, Per H. Christensen, Wojciech Jarosz
We present photon beam diffusion, an efficient numerical method for accurately rendering translucent materials. Our approach interprets incident light as a continuous beam of photons inside the material. Numerically integrating diffusion from such extended sources has long been assumed computationally prohibitive, leading to the ubiquitous single-depth dipole approximation and the recent analytic sum-of-Gaussians approach employed ... more
Additional materials: [supplemental-theory.pdf], [PBD_matlab_v1.03.zip]
Published in Computer Graphics Forum (Proceedings of the Eurographics Symposium on Rendering 2013), volume 32, number 4. Eurographics / Blackwell Publishers, June 2013. (Zaragoza, Spain, June 19-21.). Equation 13 amended July 2013.
The Path to Path-Traced Movies|
Per H. Christensen, Wojciech Jarosz
Path tracing is one of several techniques to render photorealistic images by simulating the physics of light propagation within a scene. The roots of path tracing are outside of computer graphics, in the Monte Carlo simulations developed for neutron transport. A great strength of path tracing is that it is conceptually, mathematically, and often-times algorithmically ... more
Appeared as: Foundation and Trends in Computer Graphics and Vision, volume 10, number 2, pages 103-175.
Orthogonal Array Sampling for Monte Carlo Rendering|
Wojciech Jarosz, Afnan Enayet, Andrew Kensler, Charlie Kilpatrick, Per Christensen
We generalize N-rooks, jittered, and (correlated) multi-jittered sampling to higher dimensions by importing and improving upon a class of techniques called orthogonal arrays from the statistics literature. Renderers typically combine or "pad" a collection of lower-dimensional (e.g. 2D and 1D) stratified patterns to form higher-dimensional samples for integration. ... more
Additional materials: [supplemental.pdf], [images.tar.xz]