Checkerboard rendering
Checkerboard rendering, also known as checkerboarding for short, is a 3D computer graphics technique, intended primarily to assist graphics processing units with rendering images at high resolutions. It should not be confused with tile rendering, another method of subdividing images in order to render them more efficiently, or the "checkerboard" method of alternate frame rendering.
Description
While exact implementations tend to vary between developers, the technique generally involves rendering only 50% of any given scene, often rendering it in a grid of 2×2 pixels. A reconstruction filter is then employed to extrapolate the appearance of the unrendered parts of the scene, with the final image then being presented to the viewer as (theoretically) the same as if it had been rendered natively at the target resolution. In some implementations the checkerboard grid will be alternated between frames, with the previous frame's image data being held in memory, and then used to aid with reconstructing the scene.[1]
Though the technique is usually employed with the goal of reducing the computational resources required to render a scene at higher resolutions, it can also be used as a form of anti-aliasing, with Rainbow Six: Siege one of the games to use it in this manner.[2]
Implementation
Games first started making use of the technique in the mid-2010s, often with the goal of making it easier for games to achieve 4K resolution at acceptable framerates.[3] The first game to use checkerboard rendering was Killzone Shadow Fall in multiplayer mode. Though the technique does not require any specific hardware support outside of the normal for games produced in this era, the PlayStation 4 Pro and Xbox One X included specialised hardware to enable checkerboard rendering to be carried out with much less of a performance loss than might otherwise be the case.[4]