**Christopher Kulla's Homepage** ![ ](images/chriskulla.jpg width="150px") Hello! This is just a small page to collect various things I've worked on. I am an Engineering Fellow for Graphics at [Epic Games](https://www.epicgames.com/) working on ray tracing and light transport in [Unreal Engine](https://www.unrealengine.com/). (#) Publications and Talks (##) 2022 * ![ ](images/digipro2022_icon.jpg width="96px" border="1") Puppetering the Pixels: Innovative Animation Tools For Stylized Rendering (Digipro 2022) *Lee Kerley, Joshua Beveridge, Dylan Reid, Dylan Gottlieb, David Allen, Stefan Herz, Christopher Kulla, Stirling Duguid, Doug Smith, Arjun Namdeo, Mike Cole* - [Conference Link](https://digiproconf.org/program/program-6/) - [Official Publisher's Link ](https://dl.acm.org/doi/10.1145/3543664.3543673) - [Preprint ](data/s2022-puppeterring-the-pixels.pdf) (##) 2021 * ![ ](images/moblur-icon.jpg width="96px" border="1") Motion Blur Corner Cases ([Ray Tracing Gems II](https://link.springer.com/book/10.1007/978-1-4842-7185-8)) *Christopher Kulla, [Thiago Ize][thiago]* - [Article ](https://link.springer.com/chapter/10.1007/978-1-4842-7185-8_12) (##) 2020 * ![ ](images/caustics-icon.jpg width="96px" border="1") Adaptive Caustics Rendering in Production with Photon Guiding (EGSR 2020 - Industry Track Paper) *[Alejandro Conty][aconty], Christopher Kulla* - [Preprint ](data/egsr_2020_caustics.pdf) - [Presentation Video](https://www.youtube.com/watch?v=CAa2APz1hUc&t=3116s) (##) 2019 * ![ ](images/s2019-course-icon.jpg width="96px" border="1") [Path Tracing In Production - Part 1: Volumes](https://s2019.siggraph.org/presentation/?id=gensub_286&sess=sess199) (Siggraph 2019 Course) - [Slides ](data/s2019_ptip_volumes.pdf) - [Course Website](https://jo.dreggn.org/path-tracing-in-production/2019/index.html) (##) 2018 * ![ ](images/s2018-panel-icon.jpg width="96px" border="1") [Design and Implementation of Modern Production Renderers](https://s2018.siggraph.org/presentation/?id=gensub_447&sess=sess271) (Siggraph 2018 Panel) - [Slides ](data/siggraph-2018-panel.pdf) * ![ ](images/mon_dj.jpg width="96px" border="1") Sony Pictures Imageworks Arnold (ACM Transactions on Graphics 2018) *Christopher Kulla, [Alejandro Conty][aconty], Clifford Stein, [Larry Gritz][lg]* - [Preprint ](data/2018_tog_spi_arnold.pdf) - [Official Publisher's Link ](https://dl.acm.org/citation.cfm?id=3180495) * ![ ](images/manylight2018_icon.jpg width="96px" border="1") Importance Sampling of Many Lights With Adaptive Tree Splitting (HPG 2018) *[Alejandro Conty][aconty], Christopher Kulla* - [Paper ](data/many-lights-hpg2018.pdf) (##) 2017 * ![ ](images/ptcourse_icon.jpg width="96px" border="1") [Path Tracing in Production](https://jo.dreggn.org/path-tracing-in-production/) (Siggraph 2017 Course) - [Slides ](data/arnold-sony-pictures.pdf) - [Course Website](https://jo.dreggn.org/path-tracing-in-production/2017/index.html) * ![ ](images/volcourse_icon.jpg width="96px" border="1") [Production Volume Rendering](http://graphics.pixar.com/library/ProductionVolumeRendering/index.html) (Siggraph 2017 Course) - [Slides ](data/volume-rendering-techniques.pdf) * ![ ](images/pbscourse_icon.jpg width="96px" border="1") [Physically Based Shading in Theory and Practice](http://blog.selfshadow.com/publications/s2017-shading-course/) (Siggraph 2017 Course) - [Slides ](data/s2017_pbs_imageworks_slides_v2.pdf) - [Sheen model report ](data/s2017_pbs_imageworks_sheen.pdf) * ![ ](images/manylight2017_icon.jpg width="96px" border="1") Importance Sampling of Many Lights With Adaptive Tree Splitting (Siggraph 2017 Talks) *[Alejandro Conty][aconty], Christopher Kulla* - [Talk ](data/importance-sampling-lights-abstract.pdf) - [Slides ](data/importance-sampling-lights-slides.pdf) * ![ ](images/smu_icon.jpg width="96px" border="1") Lighting Up The Smurfs Enchanted Forest (Siggraph 2017 Talks) *Xinling Chen, Christopher Kulla, Lucas Miller, Alan Chen* * [Talk ](data/smurfs-abstract.pdf) (##) 2013 * ![ ](images/woz_icon.jpg width="96px" border="1") Oz the Great and Volumetric (Siggraph 2013 Talks) *[Magnus Wrenninge][magnus], Christopher Kulla, Viktor Lundqvist* - [Talk ](data/oz_volumes.pdf) * ![ ](images/bssrdf_icon.png width="96px" border="1") BSSRDF Importance Sampling (Siggraph 2013 Talks) *Alan King, Christopher Kulla, [Alejandro Conty][aconty], Marcos Fajardo* - [Talk ](data/bssrdf.pdf) - [Slides ](data/bssrdf_slides.pdf) (##) 2012 * ![ ](images/teapots_atmo.jpg width="96px" border="1") Importance Sampling Techniques for Path Tracing in Participating Media (EGSR 2012) *Christopher Kulla, Marcos Fajardo* - [Paper ](data/egsr_2012_volume_paper.pdf) - [Slides ](data/egsr_2012_volume_talk.pdf) (##) 2011 * ![ ](images/equiang_icon.jpg width="96px" border="1") Importance Sampling of Area Lights in Participating Media (Siggraph 2011 Talks) *Christopher Kulla, Marcos Fajardo* - [Talk ](data/sketch01_importance_sampling_v2.pdf) - [Supplemental ](data/sketch01_importance_sampling_supp_v2.pdf) - [Slides ](data/sketch01_importance_sampling_talk_v3.pdf) * ![ ](images/decoupled_icon.jpg width="96px" border="1") Decoupled Ray Marching of Heterogeneous Participating Media (Siggraph 2011 Talks) *Christopher Kulla* - [Talk ](data/sketch02_heterogeneous_v2.pdf) - [Slides ](data/sketch02_heterogeneous_talk_v2.pdf) (##) 2010 * ![ ](images/osl_icon.png width="96px" border="1") Open Shading Language (Siggraph 2010 Talks) *[Larry Gritz][lg], Clifford Stein, Christopher Kulla, [Alejandro Conty][aconty]* - [Talk ](data/osl_sketch.pdf) (##) 2003 * ![ ](images/npr-paint-icon.jpg width="96px" border="1") Using Texture Synthesis for Non-Photorealistic Shading from Paint Samples (Pacific Graphics 2003) *Christopher Kulla, James Tucek, [Reynold Bailey](https://www.cs.rit.edu/~rjb/), [Cindy Grimm](http://web.engr.oregonstate.edu/~grimmc/)* - [Paper ](data/npr-paint-2003.pdf) [aconty]: http://www.aconty.com/ [magnus]: http://magnuswrenninge.com/ [lg]: http://www.larrygritz.com/ [thiago]: http://www.sci.utah.edu/~thiago/ (#) Personal Projects [Sunflow](http://sunflow.sourceforge.net/): An open source rendering system for photo-realistic image synthesis. [Buddhabrot Fractal Renderer](http://www.flickr.com/photos/fpsunflower/sets/72157618708053097/) [Tiny OpenEXR output](https://gist.github.com/fpsunflower/e5c99116ff94114d1cbe) [Tiny PNG output](https://gist.github.com/fpsunflower/a79b06e92968465397d4) [Tiny bitmap font rendering](https://gist.github.com/fpsunflower/7e6311c9580409c115a0) [Tiny float to ascii conversion](https://gist.github.com/fpsunflower/c98f8b6099088c3b8bf630ee3d6b773d) (#) Short Bio Christopher Kulla is an engineering fellow for graphics at Epic Games where he focuses on ray tracing and light transport. He previously worked at Sony Picture Imageworks on the in-house branch of the Arnold renderer for 13 years, making contributions to ray-tracing kernels, sampling techniques and volume rendering. In 2017 he was recognized with a Scientific and Engineering Award from the Academy of Motion Picture Arts and Sciences for his work on the Arnold renderer. (#) Other Links [Github](https://github.com/fpsunflower/) [Shadertoy](https://www.shadertoy.com/user/fpsunflower) [LinkedIn](https://www.linkedin.com/in/ckulla/) [Google Scholar](https://scholar.google.com/citations?user=HleuowoAAAAJ)