1. A computer graphics system for processing data representative of objects as to provide an image to a viewer, comprising: means providing a coordinate array register; means for providing said data as coordinate signals representative to points to exhaust the display surface and with greater resolution than said coordinate array register, said points being defined on said objects in viewing screen coordinates; and means for testing said coordinate signals for registration in said coordinate array register whereby to selectively register signals for viewing screen coordinates nearest to said viewing screen as to eliminate hidden components to the image.