Viewpoint setting apparatus for a computer graphics system for displaying three-dimensional models

Claim 1

A viewpoint setting apparatus for setting a viewpoint, provided on a three-dimensional model, on a display monitor in a computer graphics system, comprising: a model information database storing three-dimensional model information including model coordinates and physical attributes thereof; a viewpoint locus database storing viewpoint information including locus data produced when the viewpoint moves on the display monitor; a field of view conversion matrix database storing a three-dimensional conversion matrix in order to change a field of view from the viewpoint; motion calculation means operatively connected to said model information database, said viewpoint locus database, and said field of view conversion matrix database, for receiving the model information and the viewpoint information, calculating the motion of the model caused by the change of the field of view based on the change of the viewpoint which is caused by physical forces applied to the model having the viewpoint, and sequentially updating the field of view conversion matrix database in accordance with the change in the field of view calculated; drawing processing means operatively connected to the motion calculation means, for receiving the result of calculation of the field of view conversion matrix from said motion calculation means, and drawing the three-dimensional model on the display monitor based on new field of view calculated by the motion calculation means; and input means operatively connected to the motion calculation means for outputting a view-parameter which adjusts the motion of the three-dimensional model so as to conform to an actual viewpoint of a user, wherein said three-dimensional model is formed by a bar-shaped model having a mass at the end thereof and a viewpoint at the top thereof.