Glass transparency issue

[chris.estuarycreative]

Hi Guys,
I wish to have a transparent surface on my model, that shows through to an LCD screen underneath. In some instances you wouldn't even know it's there, it would be noticeable when the light hits it from certain angles. I believe I've set everything up accordingly but the surface just renders black. I have a parameters tag with the opacity unchecked, Custom Parameters IS checked, I've used an Arnold sky object and have turned transmission samples down as I've read that to be an issue. In short, I have tried everything and still not what I want!

I've got the latest v5 (trial) installed on r20

p.s. ignore the noisy renders, I just wanted to illustrate the problem. It's a WIP...

It's the lcd screen with the vinyl indicator I want to see through a glass cover.

[Eden_Soto1]

I've run into that issue before and I think it was a Transmission depth issue for me... have you tried adjusting that?

[chris.estuarycreative]

@Eden Soto hi Eden I have set it to 0.5 / 1 / 100 and so on and nothing. tried caustics = nothing / aovs = nothing etc etc

[lee_griggs]

Are the normals facing the right direction? Is it double sided? If not, are you using Thin Walled? What happens when IOR is 1?

[chris.estuarycreative]

@Lee Griggs Hi Lee, I switched on Thin Walled but it didn't change THEN I dropped the cutout opacity to 50% grey and the item I want to show then appeared. But I don't think that's the answer, because I then moved my light to see if I got a reflection to show on this peice of glass and nothing…

[lee_griggs]

Did you try Max's recommendation of enabling caustics?

[chris.estuarycreative]

Guys, thanks for your suggestions. It so happens it was an issue with the HDRI link plugin I use, the GSG one, attached to an Arnold Sky object. I just deleted it, rebuilt it – dead simple – and it works.