Another test, prompted by the LuxRender forums and the new volume definitions of 0.7.
This time it is fake subsurface scattering, Though i am not 100 % sure how this works within luxrender. If you want to render something like… wax, where light passes through it enough to make it glow, but not make it transparent. Mattetranslucent material does a reasonably good job at this, however it gives everything an extremely flat appearance and doesn’t provide a realistic look or much flexibility. The problem is mainly the colour and texture.
In this example we have a mix of glossy and mattetranslucent, to give a glossy but transparent look. We also define the inner volume to be a glassy like volume with a adsorption color and depth. This gives the impression that if the light passes through a huge body of material, you just don’t see anything out the other side, if it is thin however, you do see it, and it has an adjusted colour and brightness!
Along with the tests on the forum i made up a quick model square based candle with a meshlight flame.
Sub Surface Scattering can look very effective, however it takes a lot of adjustment. These two objects where very quickly put together and are the product of about 6 re-renders after i had decided i didn’t like how they look. Im would not say that they are ultimately looking great. There are many other things you can do to get an subsurface scattering effect, another one is to double up the mesh. I haven’t had the chance to do this yet however.
In this example, the material is a 0.7000 mix of Glossy and Mattetranslucent .
External Volume is Air
Internal Volume is Clear, glass with a assigned adsorption colour with a depth of 0.25m