3ds Max: Mental Ray glass shader-why does glass render black?

Cordell Felix

I rendered a scene from 3drender.com for one of my classes midterms..
when i render glass that is in front of or behind another glass bottle it will render black.

So pretty much any over lapping glass will render black..how do i fix this and what is causing the problem?

rebb

Looks like what happens when there are not enough refraction/reflection rays set in the render settings.

Firebert

Depends on any number of things.

What material library is this material from? Is it an arch viz mat, mental ray mat, etc? Refraction settings in the material itself play a big role in how they render. Finally, you need to have high raytrace settings, as well as modified FG/GI/Caustic settings for glass to render properly.

Start off with amping up your raytrace values in the render options, then look at your material settings. Do test renders with and without FG/GI and Caustics to start out. Do individual test renders for those as well, and save out maps for each one, then you can see how they look blended and readjust accordingly.

It takes a long time to render anything out realistically. How lights interact with materials in a scene can vary from scene to scene to scene. This is one reason why studios set up light rigs for characters in films. If you wanna get really good at doing material and lighting, you will need to study up on the math and what is actually happening in the background... this is the role of TDs

Cordell Felix

Oh yea, totally forgot to mention that you were right firebert.
So thank you!
here was the finished render.