Real-Time 3D Lettering with a 2D Font Engine

Abstract

Standard texturing shows a number of problems with 3D objects such as road signs, labels, or books. If letters are displayed at too large a scale, textures show blurred instead of hard edges; if letters are displayed at tiny sizes, textures appear either too pixelated or too blurry, but seldom well readable. In 2D as opposed to 3D, letters are created on demand in the required size by a sophisticated font rendering engine, a standard component of today s operating systems. A number of specific improvements such as hinting and RGB subpixel rendering are available. This paper demonstrates how these partially proprietary and patented 2D functions can be leveraged for 3D rendering. The price to pay is a loss in geometric precision, since typical 2D font rendering engines only handle affine transformations, which can merely approximate perspective projection. However, in most situations this is outweighed easily by the gain in clarity.