An array used to store the maximum Z coordinate of any feature plotted at a given (X, Y) location on the screen, used for hidden line remoVAL in a 2D rendering of a 3D scene. The Z axis is perpendicular to the screen with VALues increasing toward the viewer so that any point whose Z coordinate is less than the corresponding Z-buffer VALue will be hidden behind some feature which has already been plotted. (1997-07-18)