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# Blinn's model (aka Blinn-Phong model)

Actually, I'm still unsure where in the paper Torrance-Sparrow's model ends and Blinn's modification begins... I guess the principal part is that about improved distribution functions... he also talks about "eventual fall-off" with deviation from surface normal.

Basically, Blinn just explains that Torrance-Sparrow's model is Phong's model combined with geometric $G$ and Fresnel's $F$ factors and $\frac{1}{\langle N, E \rangle}$ distribution term (since "total surface area of facets pointing in direction of (?) is inversely proportionaly to the cosangle of the tilt, i.e. the cosangle between $E$ and $N$")