Billboard (3D graphics)

Billboards are textured rectangles that are used in 3D computer graphics to simplify models. They are generated by the planar projection of the model to be simplified onto a rectangle. Since this projection breaks down a model that can consist of several thousand polygons into just 2 polygons, which are necessary for the representation of the rectangle, billboards are particularly interesting for real-time applications. Often transparency is necessary in the implementation.

Computer games

In computer games, billboards are z. B. used to display trees and bushes that are further away from the player. The display in the game can be done in different ways:

• By a billboard, which is rotated with the movement of the camera so that its front always faces you, or
• through two static, intersecting billboards.

A particularly trend-setting implementation was seen in 2004 in the German game Far Cry . The SpeedTree middleware solution also uses these techniques.

See also

• Sprite (computer graphics)

Web links

• Document from Microsoft MSDN , online resource, accessed November 2009
• Explanation ( memento of November 28, 2012 in the web archive archive.today ) of the spherical billboarding in the L3de blog (German)

Remarks

1. ↑ In Windows DirectX e.g. E.g. two right-angled triangles, which are (would be) only visible from one side, can be avoided, see culling .
2. ↑ In DirectX : e.g. E.g . : alpha channel .