VRay Glass - Transparent from inside - Dark almost non Transparent from Outside

[blaxxun]

Dear Forum,

 

I have a scene with an Airport.

 

A very long straight corridor with Glass on the left and right side.

From this corridor there are several passenger bridges leading in a 90 Degree

angle to the Airfield where the Planes are docking.

Also this passenger bridges have Glass on the left and right side when you enter them.

 

So from outside the Glass looks very dark brownish little reflecting. Almost non transparent.

 

From the Inside the Glass is very transparent and just very slightly darker than clear Glass.

 

My question now is.

How Can i achieve this effect in VRay??

 

The Glass is a very thinwalled Object. Its not a single plane which would give wrong

IOR of course.

 

I tryd several things but somehow it doesent work.

I also tryd to seperate the outer polygon from the rest of the Glass and made each singlesided in the hope to workaround with the normals.

Also this doesent work very well.

 

So i ask the Pro's on how to achieve this.

 

Thanks in advance!

[BrianKitts]

Do not make your glass %100 refractive, give it a bit of a tint to achieve the affect you're looking for. It's a matter of making sure that the lights outside are much much brighter than the interior lighting. Then set your camera exposures to balance the shots so that the lighting works for each scheme.

 

You're basically asking to replicate reality which is completely possible, but keep in mind exterior lighting is so much brighter than interior lighting that your interior scene would have a blown out exterior.... similar to the following image.

 

http://www.google.com/imgres?q=airport+terminal&um=1&hl=en&sa=N&biw=1293&bih=779&tbm=isch&tbnid=0EYiUoBQWwwoSM:&imgrefurl=http://thewondrous.com/top-ten-most-beautiful-airports-of-the-world/&docid=3Gl6j1PYKDncBM&w=800&h=533&ei=4O9cTobCMsbiiAL-uaSzBQ&zoom=1&iact=rc&dur=293&page=1&tbnh=143&tbnw=205&start=0&ndsp=20&ved=1t:429,r:16,s:0&tx=156&ty=98

 

so if you're trying to break reality...... then it's all down to adjustments and working the balancing act of 5 parts, interior lights, interior cam exposure, exterior sun, exterior cam exposure, and your glass settings.

 

All that being said it's for this reason most people break their models up into multiple scene files and keep the interior and exterior lighting setups different. You can xref your scene into multiple files and have different lighting setups for each and save yourself the hassle of holding one ear hopping on one foot while trying to crack open your beer with a flamingo.

Edited August 30, 2011 by BrianKitts

[blaxxun]

Hello Brian,

 

Thanks for the swift reply.

 

As it seems i have to break reality in my situation.

I use baked 8K textures for the whole Airport. More than 100 of them.

To handle the memory problem i use the ecw wavelet Format and the WavGen plugin.

 

So in my final scene the lights are only used for Specs. And the only thing to Render is the Reflections and Refractions.

 

I have to find a way to make the Glass dark outside and totally transparent from the inside.

 

Looking from the main corridor to the passenger bridges through the very transparent glass at the very dark glass.

 

I also thought of duplicating all the glasses and use animated visibility so i can switch when the camera is at a dead angle

so the Trick is not visible.

 

The problem is just that there are more than 40 cameras.

 

For me every trick is welcome.

 

Maybe there is a way to make a polygon invisible when the normals point away from the camara and visible when the normals point TO the camera.

 

Thanks in advance!