Need help with iray glass shader.

AnotherUserName

So I'm trying to create a scene that is viewed from the interior of the ShuttleStar model by Kibaretto.The camera is in the cockpit and looks out the front view port of the ship. I have used the iray Glass-Solid-Clear shader on the view port windows. Surrounding the shuttlestar is the FM Solar System stardome by Flipmode which I have used with the iray emissive shader to provide ambient light from the stars. Everything looks great! The interior of the shuttlestar looks fantastic and the stars shine brightly, etc. The problem is that the Allied Fleets Frigate by Skynet3020 is nowhere in sight and it should be right smack in front of the ShuttleStar. The Frigate has been shaded with the iray base shader and the windows have been lit up by the emissive shader.

Thinking that perhaps I had an opacity channel turned down somewhere I checked all the surface tabs and they were fine. I hid the Shuttlestar and rendered the scene. There was the Frigate right where it should be. I unhid the ShuttleStar, rendered, and once again the frigate disappeared, no outlines, no lights, nothing.

So I'm stumped. I'm assuming that there is something that I need to check with the glass shader settings but I wouldn't know what that is. Anybody have any ideas?

Thanks.

mjc1016

Is the glass in the Shuttle actual modeled panes or is it just a single thickness/poly?  If it's not modeled, then the Glass-Solid is treating everything on the other side as being 'IN' the glass and absorption is kicking in.  You'll need to try some of the other glass...thin wall or something like that.

AnotherUserName

Ah, thin wall did the trick. Thank you much.

I'm curious though, why would I be able to see the emissive lights from the star dome and not the emissive lights from the frigate with thin wall off?

mjc1016

When dealing with a PBR, the more 'realistic' the geometry, the easier it is to work with.  In the real world, glass has thickness...two sides and a 'volume' in the middle...all glass.   A single poly 'window' defines only one side and the start of the volume.  There's no other side/end of the volume.  So the shader treats everything on the 'other side' as if it were part of the volume/stuck in the glass.  That's when strange things happen...with a 'black hole' being one of the real common ones.

AnotherUserName

Good to know. Thanks for the help.

acanthis

This has been really useful. I recently encountered this problem with a character viewed from the inside of a car model, through a windscreen to which an iRay glass shader had been applied. The character was there but their hair was not! Bizarre. Only when I experimented did I discover that using a thin glass shader cured my character's baldness ... and now I know why!

This info should probably be stickied somewhere.

Anyway, mjc1016, thanks for that.

Wanderer

Still useful information after all this time. I needed this.