Repeating pattern simulation of a polygon face object system

Abstract

The terrain objects within the data base for an aircraft flight simulation system are formed by polygon faces and include certain objects formed by repetitive patterns of equally spaced identical polygon faces. More specifically, objects such as runway markings, which are a series of elongated narrow rectangles equally spaced along the length of the runway. The image data is arranged in a particular format including instruction words for identifying the type of data in the data words following each instruction word, and for controlling the flow of data through the image processor. The image data formatted and processed includes: Initialization vectors (Vo), defining the position of landmark points (i.e., the first vertex of the initial polygon of each series of faces). Delta data (shape data), defining the position of other points, (i.e., the remaining vertices of each initial face) with respect to the initial point therefor. Increment data defining the uniform spacing between adjacent identical faces of each series. Series data defining the number of identical faces in each series. The image processor translates initial position data into the aircraft coordinate system, then rotates, clips, and projects each three-dimensional position vector to form two-dimensional display vectors (Vd). Raster scanlines are generated from the display vectors Vd of each face for display on a CRT.