Reflections Refractions

[Jim Meston]

A modelling, rendering question.

I have a diamond set into a piece of silver.
The silver has the shape of the diamond booleaned such that the surfaces of the diamond and the silver are in contact.
This seems to produce a decent visual result but the rendertimes have shot up by a factor of 5 or so.

What is the best method for vray rendering and indeed modelling for vray (in this case) when it comes to interpenetrating of congruent surfaces? and by extension what is the nested dielectric workflow with vray?

Thanks for any input,
Jim

[joconnell]

Hmm - if they're perfectly in contact it sounds like a nasty situation for a raytracer with co-planar faces. The standard approach for vray for surfaces that are supposed to be touching off each other (think liquid in a glass) is to have them interpenetrate / overlap slightly and vray will understand the intention and give you the correct look.

[Jim Meston]

Cool. I think in this case with a diamond in a setting, it should be the opposite and have the diamond sit back. I think I was just being dumb.
Good to know that Vray handles some kind of nested dielectric though. It would be nice if it was a bit more explicit.

[joconnell]

Yeah. With any raytracer it get's really confused when two surfaces are lying directly on each other, it can't tell what to do and you get slowdowns and shading errors. As you said you can pull the diamond back a tad and for refractive surfaces that are supposed to touch (say the diamond on another piece of diamond) go for a tiny overlap.