[itsallgoode9]

A big question came to mind tonight when working with a glossy plastic: how do you handle the ND setting when working with shiny non transparent materials (coated shiny plastics, wood with clear-coat etc)? Should I treat the ND on the gloss layer just as I would any transparent material, such as glass or plastic?

The reason I'm confused about this is because of the way ND affects opaque and dull surfaces compared to the way it affects transparent shiny surface compared to the way if affects opaque shiny surfaces. Below are the reasons I am confused:

-opaque dull surface with are really spread out highlight will have a very low ND setting
-shiny transparent material (such as glass) will have a very low ND setting
-opaque shiny material (such as chrome) will have a very high ND setting

Should I treat the gloss coat more as if it was a transparent material, such as glass, with a very low ND setting? Or should I treat it more has a very shiny chrome material with a high ND? When you are using a BDSF as a gloss coat it isn't being transparent and refracting anything since the transmittance is set as black, so therefore it seems like I should actually treat it as a shiny opaque material such as chrome and give it a high ND. But at the same time it is being used as a transparent material so I think i would use something closer to the glass/liquid range.

In the end, I guess I don't fully understand how the ND setting differs for opaque vs transparent materials and how to set it accordingly. A long post as always, sorry!

[Half Life]

Treat the Nd of the "coating" as the Nd of that material ie: An Acrylic clear coat over a diffuse plastic will have an Nd of 1.491 for the "coating".

Make sure you use Force Fresnel for those coatings/additive layers... or the reflectance 0 and 90 values will skew the results.

Best,
Jason.

[itsallgoode9]

perfect! Thanks for the response