This function returns a color, which is the specular attenuation 
of light coming from the direction L, reflecting toward direction V, 
with surface normal N and roughness rough. This is the same nonstandard
reflection model found in PRMan's specular() function. 
It is multiplied by the co-efficient Ks and the highlight color HI.
refer to the RenderMan Shading Language Extensions for 3.7.

Must be a float.  Defaults to 1.0.
This is the co-efficient for the specular function.
It controls the intensity of the returned color.
For best results Ks should range from [0,1].
refer to the RenderMan Shading Language Extensions for 3.7.

This must be a color.  Default is white.
This is the color of the highlight on the surface.
It tints the color returned from the specular function.
refer to the RenderMan Shading Language Extensions for 3.7.

This must be a normal.  The default is the surface normal, N.
This is the normal of the surface point to be shaded, P.
refer to the RenderMan Shading Language Extensions for 3.7.

This must be a vector.  The default is the light vector, L.
refer to the RenderMan Shading Language Extensions for 3.7.

This must be a vector.  The default is the opposite of eye vector, -I.
refer to the RenderMan Shading Language Extensions for 3.7.

Must be a float.
This determines the roughness or shininess of the surface,
by controling the falloff rate of the specular highlights.
refer to the RenderMan Shading Language Extensions for 3.7.

This function returns a color, which is the specular attenuation 
of light coming from the direction L, reflecting toward direction V, 
with surface normal N and roughness rough. This is the same nonstandard
reflection model found in PRMan's specular() function. 
It is multiplied by the co-efficient Ks and the highlight color HI.
refer to the RenderMan Shading Language Extensions for 3.7.