COMPUTER-READABLE STORAGE MEDIUM HAVING INFORMATION PROCESSING PROGRAM STORED THEREIN, INFORMATION PROCESSING APPARATUS, INFORMATION PROCESSING SYSTEM, AND INFORMATION PROCESSING METHOD

摘要

A game apparatus takes an image of a marker placed in the real space. The game apparatus calculates the position and the orientation of the marker with respect to the game apparatus on the basis of the marker included in the taken image, and sets a marker coordinate system on the marker. In addition, the game apparatus detects the direction of gravity on the basis of acceleration detected by an acceleration sensor included in the game apparatus. Next, the game apparatus calculates the direction of gravity in the marker coordinate system on the basis of the detected direction of gravity, and determines the orientation of the virtual character on the basis of the calculated direction of gravity in the marker coordinate system. Then, the game apparatus displays the virtual character on a display device.