Rainy windows?

[snivlem]

Sorry guys solved -please delete thread.

[Svetlozar Draganov]

And what was the solution to the issue Just in case if someone else falls into the same situation.

[snivlem]

Good point!

Initially I had modelled physically correct windows (ie they were thick).

The main problem was that if I applied a "rain drop" bump map to the windows to make it look as if rain appeared on the windows, the rain would appear in the interior as well as the exterior.

If I made the windows a plane, the bump map would not render and besides it is not accurate to have infinitely thin glass anyway
If I kept the windows thick, but assigned two materials to the window (bump mapped glass on the outside, clean glass on the inside) - VRay would break fog and refraction settings as it would treat the same bit of glass as two separate glass.

In the end it was as simple as giving the glass one material, but using UV maps on the interior to avoid rain drops on the interior plane - so you get rain on the exterior and no rain in the interior. Simple but slipped my mind!

The results are pretty convincing with bump maps.