Patent ID: 7245298
Filing Date: 2007-07-17
Classification: G06T

Abstract:
1. A game system for projectively transforming a plurality of polygons, which form a three-dimensional object located in an imaginary three-dimensional space, to a viewpoint coordinate system to draw the polygons on a projection plane of a display, comprising: a polygon drawing means for drawing a polygon of the three-dimensional object and displaying the polygon in a frame image presented on the display, the polygon having a first texture representative of a surface of the three-dimensional object and imposed on the polygon of the three-dimensional object, said first texture including a mixing ratio of the first texture which affects drawing of a second texture onto the first texture so as to determine a mixing of the first texture and the second texture, wherein the second texture is also representative of the surface of the three-dimensional object; a calculating means for calculating two-dimensional coordinates of the second texture, which is a still image texture prepared in advance, by projectively transforming three-dimensional coordinates of vertexes of the polygon of the three-dimensional object, drawn by the polygon drawing means, onto an imaginary two-dimensional plane which is prepared in advance and corresponds to two-dimensional coordinates of the second texture to produce two-dimensional vertex coordinates of the second texture which correspond to projections of the three-dimensional coordinates of the vertexes of the polygon of the three-dimensional object; a second texture drawing means for drawing the second texture on the polygon displayed of the three-dimensional object, the drawing of the second texture being effected using the two-dimensional vertex coordinates of the second texture calculated by the calculating means to determine a portion of the second texture drawn on the polygon, wherein the first texture and the second texture are mixed to effect transparency based on said mixing ratio of said first texture to effect the drawing of the second texture onto the first texture; and a texture moving means for moving in the display the second texture, drawn by the second texture drawing means, on the polygon of the three-dimensional object drawn by the polygon drawing means and displayed in the display, the moving being effected by successively varying two-dimensional vertex coordinates of the portion of the second texture used by the second texture drawing means in time-series relative to the two-dimensional vertex coordinates of the second texture previously calculated by projectively transforming the three-dimensional coordinates of vertexes of the polygon, so that the second texture appears as an image moving relative to the polygon when displayed.