The Order: 1886 Devs Explain Tech for Shadows and Materials; “Just Getting Started” Maxing Out PS4
The upcoming PS4 exclusive The Order: 1886 definitely pushes the technolofy envelope in many aspects of its rendering, and Ready at Dawn’s Graphics and Engine Programmer Matt Pettineo has been sharing what kind of techniques are being used to achieve the level of realism we’re seeing in the game.
We use SDSM + EVSM
This technique, researched by Intel Tech Lead Andrew Lauritzen (you can read about his research here), implements Sample Distribution Shadow Maps with Exponential Variance Shadow Maps reducing light bleeding and artifacts, producing higher quality shadows than traditional Z-partitioning, saving development time and also guaranteeing efficient memory usage.
We use GGX for most materials. For skin we’re using pre-integrated SSS. There’s more details in our course notes from SIGGRAPH.
The GGX shader is a microfacet model that recreates light reflection from surfaces in a realistic and believable way, while pre-integrated skin shaders calculates shading for the skin based on pre-integrated physically based profiles. Basically it divides all skin lighting between head level lighting, bump level lighting and shadow. While head level lighting takes care of large surfaces, bump level simulates lighting on smaller details.
Interestingly enough, Pettineo had a discussion with Lauritzen himself on Twitter. Lauritzen advised to use pixel shaders instead of compute, and Pettineo’s repsonse seem to hint that The Order: 1886 may already be using asynchronous compute on the PS4′s GPU.