patricks wrote:
i will say it in a different way "Indigo , Kerkythea and Radium are doing it correct ....... the other commercial unbiased render engines that where mentioned in this threat , i am not convinced that they do it correct because of the way they handle layered weight materials

"
I was very suspicious of this when I tried out the Maxwell demo. The way that the plastic material is modeled (layered) did not make sense to me.
The way I understand it, is that the Maxwell and Fryrender plastic materials are equivalent to an Indigo material that is a blend between a diffuse material and a non-transparent Specular material with IOR of 3.
Blend factor would be 0.8 (80% diffuse).
AFAIK in Kerkythea, this would be equivalent to a layered material with 80% diffuse and 20% Dielectric. Of course in Kerkythea, you can use the Fresnel ramp to set the material weights so that Fresnel reflection is taken into account.
What I don't get is why the Maxwell and Fryrender plastic materials appear to render slower in the above tests. You would think that they would render faster IF they are indeed neflecting the Fresnel effect.
BTW, patricks, you should post the link to your Kerkythea material guide that explains the differences between how to set up plastic materials. It is very imformative!
Whaat