| OCR Text |
Show Table 2.1. Notation conventions for shading model descriptions. i x is a geometric vector, a direction x x is a geometric vector of unit length x x is a wavelength-sampled vector II ill the length of i x ® y termwise multiplication of x and y , yields a vector x · y dot product of x and y , yields a scalar value Table 2.2. Terms for discussion of shading models. Table of Symbols for Shading N normal to surface l vector from surface to light E vector from surface to eye R vector specularly reflected from surface 81 angle between fJ and l, angle of icidence i intensity illuminating a pixel i, intensity of the light source ja intensity of the ambient light j• intensity due to reflected light it intensity due to transmitted light r reflectivity of a surface r4 ambient reflectivity of a surface fd diffuse reflectivity of a surface f, specular reflectivity of a surface k4 ambient light reflection coefficient kd diffuse light reflection coefficient k, coefficient of specular reflection kt transmission coefficient c constant selected so intensities result in a given range u constant greater than zero and less than two w constant between 20 and 60, controlling highlight width 5 |
