Patent Document ID: 4821212
Application ID: 06638707
Patent Status: 1

Claim One:
1. In combination in a system for the real-time computer generation and display of visual scenes: (a) display means; (b) first memory means for storing a grid data base of elevation posts at predetermined intervals for the visual scene to be generated; (c) second memory means for storing a grid data base of display data for corresponding ones of said elevation posts; (d) view ray generator means for defining a horizontal field of view as a predetermined number of sweeps perpendicular to a boresight at a view point, incrementing the change in range R from the view point and defining for each sweep the changes .DELTA.X and .DELTA.Y in said elevation post data base, accumulating .DELTA.X and .DELTA.Y to generate an X,Y data base address for reading from said first memory means the elevation data for that address, stepping a view ray down for each range increment .DELTA.R by an increment of .DELTA.RTan.phi..sub.m where .phi..sub.m is the view angle for the m.sup.th view ray, stepping the distance between sweeps by the increment .DELTA.R.DELTA.Tan.phi. for each range increment, .DELTA.R, comparing at each range increment the accumulated elevation value of the view ray with an elevation value input for said X,Y data base address, and if a view ray strikes an elevation post, reading display data for that post from said second memory means to said display means, otherwise reading the elevation data for the next elevation post from said elevation post data base and repeating said comparison; (e) first and second interpolator means through which said elevation data and display data are respectively read to provide interpolated values of elevation and display data with interpolation levels varying inversely with range; (f) third and fourth memory means respectively storing elevation data and display data values for a texture data base corresponding to a substantial part or all of said grid data base; and (g) means for reading from said texture data base delta values of elevation data and display data, adding the delta value and interpolated value of elevation data and applying the sum as the elevation value input for said X,Y data base address in said view ray generator, and multiplying the delta value and interpolated value of display data and applying the product as the display data input to said display means, thereby to add three-dimensional texture to the visual scene as represented on said display means.