NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM STORING IMAGE PROCESSING PROGRAM, IMAGE PROCESSING SYSTEM, IMAGE PROCESSING APPARATUS, AND IMAGE PROCESSING METHOD

An exemplary image processing system first writes normal line information and color information into the G buffer and depth information into the depth buffer for a first object. Next, at a time of writing the normal line information into the G buffer for a second object, the exemplary image processing system calculates a difference between the depth information of a first object and the depth information of the second object, and blends the normal line information of the first object with the normal line information of the second object based on the difference, and writes the blended normal line information into the G buffer. The exemplary image processing system then renders an image in a frame buffer based on information stored in the G buffer and light source information.