Concept
In first person video games, the field of view or field of vision (abbreviated FOV) is the extent of the observable game world that is seen on the display at any given moment. It is typically measured as an angle, although whether this angle is the horizontal, vertical, or diagonal component of the field of view varies from game to game. The FOV in a video game may change depending on the of the rendering resolution. In computer games and modern game consoles the FOV normally increases with a wider aspect ratio of the rendering resolution. The field of view is usually given as an angle for the horizontal or vertical component of the FOV. A larger angle indicates a larger field of view. However, depending on the FOV scaling method used by the game, it may only affect the horizontal or the vertical component of the field of view. The horizontal and vertical FOV are calculated from the following equations: where r is the , w and h are the width and height, and H and V are the horizontal and vertical FOV. The different values for horizontal and vertical FOV may lead to confusion because the games often just mention FOV and not whether they mean the horizontal or vertical FOV. Including peripheral vision, the visual field of the average person is approximately 170-180 degrees. Console games are usually played on a TV at a large distance from the viewer, while PC games are usually played on computer monitors close to the viewer. Therefore, a narrow FOV of around 60 degrees is used for console games as the screen subtends a small part of the viewer's visual field, and a larger FOV of 90 to 100 degrees is usually set for PC games as the screen occupies a larger amount of the viewer's vision. Narrowing the field of view can be a technique used to improve performance, as it can allow you to have to render less objects through the common optimisation technique of Viewing-frustum culling. Many PC games that are released after 2000 are ported from consoles, or developed for both console and PC platforms.
