i remember reading that one of them was more correct and another was an faster approximate epresentation, going on that ild say (A) was the correct method. but in testing they’re both very similar and IMO ild say (B) looks better, so anyways, in short im in my normal mindstate confusion.

after reading the pdf, when i said “and IMO ild say (B) looks better” in the initial question it seems as if it looks better cause it is accurate, dam now ive gotta change over from A->B

suppose alpha is the angle between normal and half-vector

suppose betta is the angle between light and reflected vector

suppose A is the angle between normal and view-vector (due to reflection bidirection it is also equal to the angle between normal and reflected vector)

suppose B is the angle between half-vector and view-vector (due to half-vector definition it is also equal to the angle between half-vector and light)

1st equation is very simple:
B + alpha = A (or ‘A + alpha = betta’ depending on your picture)
2nd euation is also not very different:
betta + B = alpha + A (or ‘betta + A = alpha + B’)

Solve it and you get:

betta = 2 * alpha

So, the angle for Phong specular equation is twice bigger than for Blinn’s one.
Imagine, that we have a directional light looking directly from our head (V is equal to L). We see it’s reflection only if we are quite perpendicular to the surface, as Phong says. But Blinn allows us to see more reflected light, which is not very natural for a perfect mirror, but it is natural for a micro-facet fuzzy mirrored surface.

Originally posted by zed: b/ seems ok if u normalize the halfvector
It will still have issues. The halfvector is not a linear attribute. You’ll see it sort of bend near triangle edges if the triangles are large.