VRay Glass Reflection Issue

[btee]

Hi,

 

I'm working on a scene and am having a problem that I've noticed on previous projects when using VRay. It's hard to describe, but I find that there's a "border" which shows up large expanses of glass; on one side of the border, my reflections/refractions work as intended, whilst on the other side of the border, they are stuffed up.

 

Please see attached image: http://img220.imageshack.us/i/reflectionissue.jpg/

 

The curved nature of this "border" makes me think that it's an issue to do with angles of reflection to the camera. I've tried to counter this by changing the falloff parameters for both reflection and refraction and turning fresnel off completely. I've also tweaked just about every other setting possible in the material editor. I should note that the glass geometry I'm using is made up of planes with a 10mm shell on them, but I have also tried substituting planar glass with no thickness - I still get the same problem.

 

I also came across this linked thread, which I thought would solve the problem for me, but didn't: http://vray.info/topics/t0106.asp I tried adjusting the "cutoff threshold" parameter (tried many different values) and I managed to make the problem more severe, but couldn't solve it.

 

Whilst I've been using VRay for many years, I've never found a solution to this issue. I'm hoping that it's simple to solve and that I'm just a bit of a twit. Can anyone help me?

 

Many Thanks,

 

BT