Glossy Refractions

Has anyone had any luck building a glossy refraction setup with the PBR shaders in UE?

The look I’m trying to emulate is etched glass, like in the picture below. I’ve tried plugging a high-res noise procedural into the refraction, however it just gets buzzy and takes a good couple of seconds to adapt between motions. If there’s a way to blur objects behind the glass sheet, and then mask them based on a map on the shader, I’d be happy to find out how.

This is a real-world example of one of the looks I’m trying to achieve. I’ve so far been able to affect the opacity and reflective qualities of the etched portions of the glass, but no luck with the glossy refraction.

I would say that this is currently not supported. In the Toolbag2 thread on polycount was also a discussion about this, and Toolbag also has no solution yet. However…someone posted a whitepaper from some guys that researched this, but it is a completely new BRDF (or better to say a BTDF which stands for bidirectional transmittance distribution function, or even more advanced have a BSDF - bidirectional scattering distribution function). To implement something like this, you would need to replace it with one of the existing shaders from UE4 because G-Buffer space is limited and you cant just add new shaders.

I had a feeling that’d be the case. Oh well, I guess I can work around it. Its not physically accurate, but at least it’ll emulate the look close enough to the untrained eye.


Hi Crow87, Did you manage to achieve or at least fake this kind of effect in the end? If so, do you have any suggestion about how to implement it?