Upon generation of an image of a virtual space on which a virtual object is laid out using a ray tracing method, an approximate virtual object, which is configured by at least one virtual element to approximate the shape of a physical object, is laid out on the virtual space. Then, intersect determination between a ray generated based on the ray tracing method and an object on the virtual space is executed. As a result of the intersect determination, when the ray and the approximate virtual object have a predetermined intersect state, a pixel corresponding to the ray is generated based on a ray before the predetermined intersect state is reached.