SIGGRAPH 2010 Course: Global Illumination Across Industries Point-Based Global Illumination for Movie Production

This course note describes a fast point-based method for computing diffuse and glossy global illumination, area light illumination and soft shadows, HDRI environment map illumination, multiple diffuse reflection bounces, final gathering for photon mapping, ambient occlusion, reflection occlusion, and volume scattering. The results are free of noise and the run-time does not increase due to displacement maps on surfaces, complex shaders, or dozens of complex light sources. These properties make the method suitable for movie production. The first step generates a point cloud (surfel) representation of the directly illuminated geometry in the scene. The surfels in the point cloud are organized in an octree, and the power from the surfels in each octree node is approximated either as a single large surfel or using spherical harmonics. To compute the indirect illumination at a receiving point, we rasterize the light from all surfels using three degrees of accuracy: ray tracing, disk approximation, and clusters. Huge point clouds are handled by reading the octree nodes and surfels on demand and caching them. The method is integrated into Pixar’s RenderMan renderer (PRMan) and has been used in the production of more than 35 feature films to date.

[1]  Dale Mayeda.  Interactive lighting of effects using point clouds in "Bolt" , 2009, SIGGRAPH '09.

[2]  Hayden Landis,et al.  Production-Ready Global Illumination , 2004 .

[3]  Robert L. Cook,et al.  The Reyes image rendering architecture , 1987, SIGGRAPH.

[4]  James Arvo,et al.  A clustering algorithm for radiosity in complex environments , 1994, SIGGRAPH.

[5]  Paul S. Heckbert,et al.  Irradiance gradients , 2008, SIGGRAPH '08.

[6]  Henrik Wann Jensen,et al.  A rapid hierarchical rendering technique for translucent materials , 2005, ACM Trans. Graph..

[7]  Pat Hanrahan,et al.  An efficient representation for irradiance environment maps , 2001, SIGGRAPH.

[8]  Henrik Wann Jensen,et al.  Global Illumination using Photon Maps , 1996, Rendering Techniques.

[9]  Sergey Zhukov,et al.  An Ambient Light Illumination Model , 1998, Rendering Techniques.

[10]  Okan Arikan,et al.  LECTURERS , 1948, Statistics for Astrophysics.

[11]  Per H. Christensen.  Faster Photon Map Global Illumination , 1999, J. Graphics, GPU, & Game Tools.

[12]  Per H. Christensen,et al.  Point-Based Approximate Color Bleeding , 2008 .

[13]  Brian A. Barsky,et al.  Advanced Renderman: Creating CGI for Motion Pictures , 1999 .

[14]  Arnauld Lamorlette,et al.  An approximate global illumination system for computer generated films , 2004, SIGGRAPH 2004.

[15]  François X. Sillion,et al.  A Unified Hierarchical Algorithm for Global Illumination with Scattering Volumes and Object Clusters , 1995, IEEE Trans. Vis. Comput. Graph..

[16]  Michael Todd Bunnell,et al.  Dynamic Ambient Occlusion and Indirect Lighting , 2005 .

[17]  Hans-Peter Seidel,et al.  DACHSBACHER C.: Micro-rendering for scalable, parallel final gathering , 2022 .

[18]  Henrik Wann Jensen,et al.  A rapid hierarchical rendering technique for translucent materials , 2005, SIGGRAPH Courses.