Quad buffering uses four memory areas to render a scene, with two independent sets of buffers used for stereoscopic displays. It helps create smooth animation and is necessary for displaying certain types of media in 3D.
In computer graphics, quad buffering is the act of using four areas of memory to render a scene, with one of the buffers being the frame currently being shown on the display device. The term also has a more specific connotation, and is used to describe double buffering as applied to stereoscopic displays, where there are two buffers for the right eye and two buffers for the left eye, with one displayed for each eye in one given given time. The use of quad buffering grew in popularity as three-dimensional (3D) display hardware started to become more common and was eventually supported by a variety of different graphics cards. Depending on the type of 3D hardware used, the buffers can either be projected onto a single screen so that special glasses can be used to view the 3D effect, or each of the buffers can be sent to a different display device, such as a head mounted display with independent projections for each eye.
The idea behind quad buffering is similar to double buffering, except that two independent sets of buffers are used. While one buffer is displayed, the second buffer has the current scene rendered. When the next frame needs to be displayed, the buffers are switched and the next frame is drawn on the buffer which is not displayed. This helps make the animation and movement feel very smooth for the viewer while keeping the framerate as consistent as possible.
With quad buffering, double buffering is done for each eye. The 3D scene in use needs to be rendered twice from two separate angles in two separate buffers. The buffers are independent of each other, so each can be displayed as needed by the hardware used for each eye, potentially ensuring that each of the frames can be rendered and displayed at different speeds for each eye.
Stereoscopic rendering using quad buffering can be used to provide a 3D view of a scene through a variety of hardware-implemented methods. It’s also important for applications designed to play certain types of media, as some video formats use 3D techniques, which means that quad buffering becomes a necessary tool to display video correctly. In some cases, the use of quad buffering and stereoscopic rendering still requires special display hardware and may create an image that is unrecognizable on standard two-dimensional (2D) monitors.
Protect your devices with Threat Protection by NordVPN
