PROBLEM TO BE SOLVED: To provide efficient techniques for generating non-photorealistic effects such as cartoon outlining in a three-dimensional videographics system. SOLUTION: Depth (Z) values are used to determine which pixels are located at object edges, and border coloration is selectively blended into those pixels which are then displayed. Object edges are located by comparing certain pixel depth values with neighboring pixel depth values. A desired border line color is blended into the pixel's color value on the basis of a distance value. In one example, the distance value is used to calculate a pixel Alpha value which is then used to control the amount of border color that is blended into the pixel color. Other examples may cause object portions with identification values stored in frame buffer normally used to store Alpha values. These ID values are used to identify object portion intersections for applying a border line color to. COPYRIGHT: (C)2009,JPO&INPIT