View Full Version : V-Ray Glass Compositing

10 October 2009, 08:14 AM
Hello !

First, sorry for my bad english but I'm a french guy !

I'm working on a Flash app, where I have to show a car in a 360° view.
I use 3dsmax (Vray 1.50 SP3a), After Effects and Flash

Users should be able to change the color of the body and also (the hardest part for me !) the opacity & tint of the glasses.

I've found a solution to change the color of the body : rendering different elements (Diffuse, GI, reflections, ..) and a color correction in after effects.

But I don't understand how I can change the opacity of the glasses in a compositing workflow.
Obviously, I've tried to render a refraction pass but I don't know how to use it later..
I also tried with a MtlSelect pass but it didn't work.

Could you please help me, or maybe tell me where I could find informations about this.

Thanks in advance.


10 October 2009, 05:20 PM
I'm not sure how you are producing this, is it a 360° pre-rendered sequence that you play
forwards/backwards into the flash clip?

My suggestion would be to render two sequences (passes) of the glass, one pass as pure glass fully refractive with reflections and another pass with full tinted glass depending on your brief.

Then simply fade from the clear glass to the tinted one and you can choose how much you want to move from one to the other, producing (or better say faking) different levels of tint.

The fully tinted glass will exhibit stronger reflections, so you might want to render those as a separate pass to control them later in the comp by screening them on top.

hope that helps

11 November 2009, 08:48 PM
Well you won't be able to get actual refractions, but what you could do is color ID the glass to give you a non-existent beauty matte for the glass. And then, in AE, use that matte as a mask for a solid. And then you can trigger a change in the opacity of the solid for a light to strong tint. The reflections that you render off of the glass surface should make it believable enough to pass for glass once composited.

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