1. A method of presenting a combined image in which a real space image of a real space is combined with a virtual image of a virtual object on a head-mounted display device for a user, the method comprising: a receiving step of receiving image data for a plurality of captured images captured by an imaging apparatus carried by the user, the plurality of captured images including images relating to different parts of the real space; a position/orientation obtaining step of obtaining position and orientation information of the imaging apparatus; a first generating step of generating modeling image data based on the received image data for the plurality of captured images and on the obtained position and orientation information of the imaging apparatus, the modeling image data representing an image covering at least a predetermined portion of the real space; an estimating step of estimating light source information relating to the real space based on the modeling image data; a setting step of setting light source information relating to the virtual object based on the estimated light source information relating to the real space; a second generating step of generating, using a processor, the virtual image based on the set light source information relating to the virtual object; a combining step of combining, using the processor, the virtual image with the real space image; and a displaying step of displaying, on the head-mounted display device, the combined image in which the real space image is combined with the virtual image, wherein the receiving step, the position/orientation obtaining step, the first generating step, the estimating step, the setting step, the second generating step, the combining step, and the displaying step are repeatedly performed in real-time.