Direction-dependent texture maps in a graphics system
AssigneeHewlett-Packard Company
InventorThomas Malzbender
Life of this patent
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Abstract
A graphics system that renders surface features of 3D object in a manner that is direction dependent but without the time consuming and expensive calculations involved in the evaluation of lighting equations on a per pixel basis. The graphics system employs direction-dependent texture maps which hold parameters that define surface structures in a manner in which the appearance of a surface structure varies in response to a direction vector. The direction vector may be light source direction or view direction. The parameters are those of a predetermined polynomial equation the evaluation of which does not involve vector calculations.
Claims20
A graphics system, comprising:
- direction-dependent texture map that holds a set of parameters for a polynomial equation that defines a surface structure in a manner in which the appearance of the surface structure varies in response to a direction vector;
- means for rendering a polygon having the surface structure by evaluating the polynomial equation using the direction vector and the parameters.
A method for rendering a 3D object, comprising the steps of:
- generating a direction-dependent texture map that holds a set of parameters for a polynomial equation that defines a surface structure in a manner in which the appearance of the surface structure varies in response to a direction vector;
- rendering a polygon of the 3D object with the surface structure by evaluating the polynomial equation using the direction vector and the parameters.
Dependencies are inferred from the claim text.