Op 29-11-2023 om 16:04 schreef Alain Martel:
> If the metal is to have a varnish coat, add a second mostly to fully 
> transparent pigment layer above the metallic one. Add an interior 
> statement for the IOR : interior{ ior 1.5 } And use the fresnel 
> attribute : reflection{ 1 fresnel }.
> 
> That way, at high angle, you'll see almost only the metallic surface, 
> but, at grazing angles, you get the fresnel reflection dominating.
> Tried that and compared with actual metals, brass actually, coated with 
> a varnish, and the result matched my physical samples.

I probably made a mistake somewhere, but I have a problem with this. The 
object looses its shadow in my code (see the egg in attached image).

This is the code used for the egg finish:

ovus { 1.00, 0.65
   pigment {rgb <0.4, 0.9, 0.4>}
   pigment {rgbt <0.9, 0.1, 0.1, 0.99>} //varnish coating!
   finish {
     metallic
     diffuse 0.0
     specular 0.80
     roughness 1/20
     reflection {0.90 fresnel metallic}
   }
   interior {ior 1.5}
   scale 0.5
   translate <0, 0.5, 0>
} // end of ovus --------------------------------------

specular / roughness can be left out without visible changes btw.

Thanks for any light on this!

-- 
Thomas

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