Crytek Senior Rendering Engineer Nicolas Schulz and Rendering Engineer Theodor Mader held a panel at the "Advances in Real-Time Rendering in Games" course at Siggraph titled "Rendering Techniques in Ryse: Son of Rome," and explained part of the advanced tech used by the team to make the game's impressive graphics possible on Xbox One.

We learn that screen space ambient occlusion was replaced with an unified screen space directional technique made of two parts, a constant part derived from indirect diffuse lighting and a directional part from direct lighting. Both were used to generate reflection occlusion, which makes quite a difference, as you can see below (you can click on each picture to load its full resolution version of each pictures, then flip between tabs in your browser for an easy comparison).

Reflection Occlusion Off

Ryse_ReflectionOcclusionOFF

Reflection Occlusion On

Ryse_ReflectionOcclusionON

The team also noticed that ambient occlusion normally causes certain surfaces to look too dark, especially on bright surfaces where absorption is low. A way to solve that was to limit the maximum ambient occlusion darkening, but that made it weak on darker surfaces. A method called AO Color Bleeding was developed to solve the issue.

AO Color Bleeding OFF

Ryse_AOColorBleedingOFF

AO Color Bleeding On

Ryse_AOColorBleedingON

MSAA was not a viable anti-aliasing option on Xbox One due to the use of deferred shading, so the team decided to use SMAA  1TX. An improved selection method from LOD (long distance level of detail models) was also implemented to get the optimal distance for transitions and minimize aliasing by avoiding the display of tiny triangles, which also improved performance.

A high quality solution was necessary for shadows in cinematics, and 2048 x 2048 shadow maps were implemented for better results.

Cinematic Shadows Off

Ryse_CinematicShadowsOFF

Cinematic Shadows On

Ryse_CinematicShadowsON

Ryse_CinematicShadowsPIC

Ryse_CinematicShadows;MAP

Ambient occlusion for large scale objects was implemented with a low-resolution shadow map (compared to the size of the objects it covered) with a 2048 x 2048 map for each square km area. Since Ryse doesn't have moving objects on that scale, it's a low-frequency effect.

The effect was very cheap on Xbox One, taking only 0.4 milliseconds of rendering time, but could be used only outdoors.

Large Scale Ambient Occlusion Off

Ryse_LargeScaleAOOFF

Large Scale Ambient Occlusion On

Ryse_LargeScaleAOON

Ryse_LargeScaleAOMAP

Large Scale Ambient Occlusion Off

Ryse_LargeScaleAOOFF

Large Scale Ambient Occlusion On

Ryse_LargeScaleAOON

Ryse_LargeScaleAOMAP

One thing is for sure, for a launch game on a console, Ryse: Son of Rome looked nothing short of fantastic. Crytek proved once more that they're the masters of graphics. I'm honestly eager to see how the game will perform on my PC. Of course you can expect a detailed analysis when the port will be released.