Patent ID: 6037946
Filing Date: 2000-03-14
Classification: G06T

Abstract:
An image synthesis apparatus for referencing depth information from a main Z-buffer which stores depth information that expresses distance from a viewpoint for each of pixels on a display screen and for drawing a display object configured by polygons, comprising:a ZR-bluffer for storing a minimum value ZMINR and a maximum value ZMAXR of depth information for the pixels within each region of said main Z-buffer, where said main Z-buffer is divided into M.times.N regions each formed of K.times.L pixels; anddrawing processing means for omitting a process of referencing depth information stored within said main Z-buffer and a process of drawing a polygon when ZMIN.gtoreq.ZMAXR or ZMIN>ZMAXR, where a minimum value or a value less than said minimum value of depth information for pixels within said polygon is ZMIN and a maximum value or a value greater than said maximum value thereof is ZMAX, and for performing the process of drawing said polygon without referencing depth information stored within said main Z-buffer when ZMAX.ltoreq.ZMINR or ZMAX<ZMINR;said drawing processing means comprising pixel drawing means and drawing judgment means;said pixel drawing means receiving polygon information that includes vertex coordinates of the polygon, drawing the pixels inside the polygon, and outputting reference requests to said drawing judgment means; andsaid drawing judgment means receiving said polygon information, obtaining ZMIN and ZMAX of the polygon based on said polygon information, determining a region to which the polygon belongs based on said polygon information, reading ZMINR and ZMAXR of the determined region from the ZR-buffer, comparing ZMIN with ZMAXR and ZMAX with ZMINR, and outputting reference results corresponding to said reference requests to said pixel drawing means.