I've been working on a bottle project, where I had set up the glassware to use decals for the embossing (only effect displacement). I thought it as working reallly well and giving me lots of control, until i realised that if the decal is not appllied the refraction looks completely different!
Decal with bump instead of displacement it still wrong. But UV mapping and applying displacement via the material works as expected - so it seems to be a decal issue.
Sometimes you hardly notice, but sometimes it is VERY different. It seems to be buggering up the IOR value of either the glass or somehow the volumetric liquid.
I can't share the real files so there's a simple scene attached below.
Unfortunately this means deacals cannot be used on transparent materials properly.
