Method, apparatus, storage medium, program, and program product for generating image data of virtual three-dimensional space

A method for generating image data of a virtual three-dimensional space viewed from a predetermined view point, comprising:

• determining a plurality of primitive surfaces including an opaque primitive surface and a plurality of transparent primitive surfaces in the virtual three-dimensional space;
• deciding a first description order of the plurality of primitive surfaces so as to give priority the opaque primitive surface over the plurality of transparent primitive surfaces;
• deciding a second description order of the plurality of transparent primitive surfaces in order of far from the predetermined view point;
• and
• performing a hidden surfaces processing to the plurality of primitive surfaces according to a Z buffer algorithm, writing color data of the opaque primitive surface in a frame buffer, and writing color data composed of color data of each of the transparent primitive surfaces and the color data written in the frame buffer, in the frame buffer, in the first description order and the second description order.