A method of displaying an illumination includes: based on illumination information, determining, using a least one processor, an illumination area to which an illumination assigned in a virtual space is projected; and visualizing, using the at least one processor, an illumination effect produced by the illumination with respect to a determined boundary area in the illumination area, the determined boundary area including a boundary and a portion of the determined illumination area that is less than all of the determined illumination area.