1. An information processing apparatus that generates a rectangular image into which a 3D scene is rendered for a predetermined viewpoint, the information processing apparatus comprising: a processor; and a memory including instructions that, when executed by the processor, cause the processor to perform operations including: obtaining a number of fragments existing on a straight line defined by the viewpoint and a predetermined point within the 3D scene to be rendered for each pixel of the rectangular image; dividing a two-dimensional region in a screen coordinate system corresponding to the rectangular image into a plurality of regions; and performing a predetermined rendering calculation for generating the rectangular area where each of the plurality of regions is taken as one unit of calculation, wherein the processor divides the two-dimensional region into the plurality of regions by at least one dividing line so that a difference of summations of the number of fragments included in each of the plurality of regions after the division becomes a minimum.