Checkerboard rendering or sparse rendering,
also known as checkerboarding for short, is a
3D computer graphics
3D computer graphics, or “3D graphics,” sometimes called CGI, 3D-CGI or three-dimensional computer graphics are graphics that use a three-dimensional representation of geometric data (often Cartesian) that is stored in the computer for t ...
rendering technique, intended primarily to assist
graphics processing unit
A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mo ...
s with rendering images at high resolutions. It is different from
tiled rendering Tiled rendering is the process of subdividing a computer graphics image by a regular grid in optical space and rendering each section of the grid, or ''tile'', separately. The advantage to this design is that the amount of memory and bandwidth is ...
, a method of subdividing images in order to render them more efficiently, and from 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.
A similar technique was used in the 1993 video game ''
Doom'', which had a "low detail" mode that only rendered every other column of pixels to improve performance.
Checkerboarding also bears a resemblance to
interlaced video
Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. Thi ...
, where every frame is split into two fields, also halving the amount of pixels that has to be rendered or transferred. Checkboard rendering differs by splitting the image using the checkboard pattern instead of splitting it by alternate line. The reconstruction filter used in checkbo