Patent ID: 6437781
Filing Date: 2002-08-20
Classification: G06T

Abstract:
In a computer graphics system, an apparatus for fog blending colors, comprising:a rendering parameter calculation unit configured to determine a cooked exponent value and a color value for at least one vertex of a primitive using primitive data, wherein said cooked exponent value is one of (log2e)(fog density)(Z-depth) and (sqrt(log2e))(fog density)(Z-depth); a rasterizer configured to interpolate said cooked exponent value of said at least one vertex to determine a cooked exponent value for each intermediate pixel in the primitive without using said Z-depth value of said intermediate pixels; a fog unit, responsive to the cooked exponent value for each pixel of the primitive, configured to determine a fog blending factor that is one of an exponential fog blending factor and an exponential-squared fog blending factor for each pixel of the primitive; and a fog blending unit that blends said fog color value with said color value for each pixel of the primitive according to said fog blending factor for the respective pixel to generate a fogged color value for each pixel of the primitive.