Need help rendering a clear dual wall container

[Rynil2000]

Hello all,

Long time renderer, first time forum poster.  I need some help getting a model to render correctly.  My model (built in SW'12) is of a clear, dual walled container (similar to a Tervis tumbler).  My problem comes when I set the materials, it seems that having two clear objects so close makes the inner one really dark.  I've tried "transparent plastic," "solid glass," and regular "glass" settings; tweaking the brightness/gamma/transparency/AOR and double sided option.  I've also tried inserting lit objects inside and in between the two objects, nothing works. 

Can anyone give me a tip on how to get the inner part of the cup to look as transparent as the outter part?

I included an image of the model rendered using "transparent plastic" and the "HDR studio bright" on the default settings for reference.

[Speedster]

First, make sure there is a small gap between the layers, like .005 - .010 or so.  If it's an assembly you can scale (mold tools) down the liner just a tiny bit. Make sure the outer skin and liner are either separate parts (I assume they are) and in a different color just to make sure KS recognizes them as separate surfaces.   Next, be sure your ray bounces are set higher- try about 12 or so.  And while you are setting up, make sure Indirect Lighting (settings tab) is checked.  Let us know how you make out- glass is always fun!
Bill G

[Rynil2000]

Wow, thanks Speedster!  After all that time, just those few tweaks made all the difference in the world.  My shots look great now!  Thanks again for your awesome tips. 

[jhiker]

Will you post one for comparison?

[Speedster]

Glad to help.  Now- show us how it looks!
Bill G

[Rynil2000]

Photo comparo!  The blue of the inner plastic is a little brighter in this one, but it doesn't change the fact that it looks 1000x better.

[Speedster]

Super!  Now, in the Scene Tree- just "lift" or raise your entire model just a tad from the ground to break the white surface on the bottom.  Try about 0.005 or so above where it's now set.
Bill G