Data structure for texture data, computer program product, and texture mapping method

Abstract

The present invention has as an object to propose a texture mapping method which enables smooth shading, and is also appropriate for conserving memory resources. In order to achieve this object, in this invention, data regions with different color tones are set so as to form density gradients in the U coordinate direction and in the V coordinate direction of the texture data. If the brightness of the surface of the object to which texture mapping is performed is I, then among the coordinates to be read to access texture fdata, the U coordinate is calculated as U=a*I+b, and the V coordinate is determined from V=d. The value of the dynamic variable d can be set appropriately according to the application. Because the texture data is such that color tone density gradients are formed in two mutually orthogonal directions, smooth shading is possible, and a plurality of texture memory areas can be consolidated to conserve memory usage.

1 - 11 . (canceled)  
   
   
       12 . A texture mapping method, which maps a texture to an object, comprising: 
 calculating first coordinate information in order to access a data region of said texture data in one direction of two mutually orthogonal directions defined for the texture data, from information set for said object surface;    calculating second coordinate information in order to access a data region of said texture data in the other direction of said two mutually orthogonal directions, from information other than information set for said object surface;    reading color data from said texture data by accessing said data region based on said first and second coordinate information; and    performing texture mapping to said object surface.    
   
   
       13 - 21 . (canceled)  
   
   
       22 . A texture mapping device for mapping a texture to an object, comprising: 
 means for calculating first coordinate information in order to access a data region of texture data in one direction of two mutually orthogonal directions defined for said texture data from information set on the surface of said object;    means for calculating second coordinate information in order to access a data region of said texture data in the other direction of said two directions from information other than information set on the surface of said object; and    means for accessing said data region based on said first and second coordinate information to read color data from said texture data and to perform texture mapping to said object surface.