This shader simulates a metallic surface.
Ka  is the coefficient to the ambient function.
Kd  is the coefficient to the diffuse function.
Ks  is the coefficient to the specular function.
Ns  is the exponent to the specular function.
AMB is the ambient color.
DIF is the diffuse color.
HI  is the highlight color.
Kr  is the coefficient for the reflection.
RFL is the reflection color. This is added to the specular color.

This must be a scalar.  The default is 0.1.
Coefficient to the ambient function, controls the intensity 
of the color returned from the ambient function.

This must be a scalar.  The default is 1.0.
Coefficient to the diffuse function, controls the intensity 
of the color returned from the diffuse function.

This must be a scalar.  The default is 1.0.
Coefficient to the specular function, controls the intensity 
of the highlight returned from the specular function.

This must be a scalar.  The default is 100.0.
Ns is the shininess, the exponent to the specular function.
It controls the rate to the falloff for the specular highlight.
The larger the exponent, the shinier the material appears,
because the falloff is more rapid.

This must be a color.  The default is GREY.
This is the ambient surface color.

This must be a color.  The default is GREY.
This is the diffuse surface color.

This must be a color.  The default is GREY.
This colors the highlight returned from the specular function.

This must be a scalar.  The default is 0.1.
Coefficient for the reflection, 
controls the intensity of the reflected color.

This must be a color.  The default is WHITE.
This is the reflection color which is to be added to the specular color.

This shader simulates a reflective surface.
This is the returned color.