The present invention is a program executed by a processing device that performs rendering processing of a virtual space including a predetermined GUI object to be displayed on a display unit of a head-mounted display device, the program causing the processing device to execute a step of determining the position of a viewpoint of a user in the virtual space; a step of determining a movable range of the user in the virtual space; a step of determining a position of the GUI object in a region of the virtual space outside the determined movable range; a step of determining, by using a perspective property profile, a size of the GUI object in the virtual space such that the GUI object at the determined position has a constant display size on the display unit; and a step of generating rendering data of the virtual space including the GUI object.