Note: This is for a single
light. If multiple lights are used, one
computes a colour for each light source (and sums all the colours up).
computational efficiency, Blinn modified the Phong model. Instead
of basing the specular reflection on the angle α
is based on the angle β between h
. Here, h
is the halfway
which is halfway between s
slightly faster to compute than r
Note though, β is a different angle than α. Using a different angle affects the specular
reflection. However, the shininess can
be modified to provide a similar effect as Phong shading.
light’s specular component ls
reflected by a surface. The amount of
light reflection at each vertex is based on the halfway vector h
surface normal n
, and the surface specular
colour resulting from the specular reflection is
where n is the shininess.