Low Altitude Texture Comparison Data Base and Smooth Shaded Texture

摘要

Various methods have been used to apply texture to computer-image ground terrain, this texture most often resembles a checkerboard or plaid pattern of multicolored squares which spread along the path of flight. With such texturing, low-level flight becomes muc h easier. Though checkerboard texture patterns make it possible to fly close to the ground, they add nothing to the realism of the scene and become monotonous after such a short time. The F-111 digital image generator (DIG) visual system has a smooth shading algorithm which can be used to create terrain texture of a different sort. Smooth shading varies the intensity of the colors on the ground in a random fashion to produce texture that is more pleasing to the eye and more natural in appearance than regular predictable checkered patterns. It has not yet been determined whether this new texturing scheme is more effective in furnishing the needed visual cues for low-altitude flight. The aim of this paper is to document the techniques used to create smooth shaded texture on the DIG and to describe the layout of a data base constructed for the purpose of comparing its effectiveness to that of a plaid checkerboard type of texture known as gingham texture.