Program and apparatus for displaying graphical objects

An apparatus for drawing and displaying an image of given objects in a three-dimensional virtual space, comprising:

• mode determination means for determining which movement mode to use, according to a given user action;
• eye point parameter calculation means for calculating eye point coordinates and a line-of-sight vector, according to the given user action and the determined movement mode;
• up direction determination means for setting an up direction of a projection plane to a predetermined direction when the determined movement mode is fixed up-direction mode, and determining the up direction of the projection plane according to predetermined rules when the determined movement mode is variable up-direction mode;
• drawing means for performing a perspective transformation of the given objects onto the projection plane being oriented to the determined up direction, based on the determined eye point coordinates and line-of-sight vector, thereby creating an image of the given objects;
• and
• display means for displaying the image created by said drawing means.

A method of drawing and displaying an image of given objects in a three-dimensional virtual space, comprising the steps of:

• (a) determining which movement mode to use, according to a given user action;
• (b) calculating eye point coordinates and a line-of-sight vector, according to the given user action and the determined movement mode;
• (c) when the determined movement mode is fixed up-direction mode, setting an up direction of a projection plane to a predetermined direction;
• (d) when the determined movement mode is variable up-direction mode, determining the up direction of the projection plane according to predetermined rules;
• (e) performing a perspective transformation of the given objects onto the projection plane being oriented to the determined up direction, based on the determined eye point coordinates and line-of-sight vector, thereby creating an image of the given objects;
• and
• (f) displaying the created image.

A computer-readable medium storing a program which draws and displays an image of given objects in a three-dimensional virtual space, the program causing a computer to perform the steps of:

• (a) determining which movement mode to use, according to a given user action;
• (b) calculating eye point coordinates and a line-of-sight vector, according to the given user action and the determined movement mode;
• (c) when the determined movement mode is fixed up-direction mode, setting an up direction of a projection plane to a predetermined direction;
• (d) when the determined movement mode is variable up-direction mode, determining the up direction of the projection plane according to predetermined rules;
• (e) performing a perspective transformation of the given objects onto the projection plane being oriented to the determined up direction, based on the determined eye point coordinates and line-of-sight vector, thereby creating an image of the given objects;
• and
• (f) displaying the created image.