Course presentation at SIGGRAPH 2014 by Charles de Rousiers and Sébastian Lagarde at Electronic Arts about transitioning the Frostbite game engine to physically-based rendering.
Make sure to check out the 118 page course notes on: http://www.frostbite.com/2014/11/moving-frostbite-to-pbr/
During the last few months, we have revisited the concept of image quality in Frostbite. The core of our approach was to be as close as possible to a cinematic look. We used the concept of reference to evaluate the accuracy of produced images. Physically based rendering (PBR) was the natural way to achieve this. This talk covers all the different steps needed to switch a production engine to PBR, including the small details often bypass in the literature.
The state of the art of real-time PBR techniques allowed us to achieve good overall results but not without production issues. We present some techniques for improving convolution time for image based reflection, proper ambient occlusion handling, and coherent lighting units which are mandatory for level editing.
Moreover, we have managed to reduce the quality gap, highlighted by our systematic reference comparison, in particular related to rough material handling, glossy screen space reflection, and area lighting.
The technical part of PBR is crucial for achieving good results, but represents only the top of the iceberg. Frostbite has become the de facto high-end game engine within Electronic Arts and is now used by a large amount of game teams. Moving all these game teams from “old fashion” lighting to PBR has required a lot of education, which have been done in parallel of the technical development. We have provided editing and validation tools to help the transition of art production. In addition, we have built a flexible material parametrisation framework to adapt to the various authoring tools and game teams’ requirements.