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Glass Reflection Problem

Posted: Mon Jun 12, 2017 9:20 pm
by Teddi
Anyone have any tips for making glass materials?

I'm trying to make a material for some glass that goes on top of two OELD screens and I keep getting the screen texture reflecting in the glass so I get a sort of double image.

On the screens in real life this doesn't happen, you can see the screen clearly from any angle without this double image issue.

I basically want the glass to just show reflections from lights and other objects but not to refract (if that's what's happening) the screen underneath.

Any ideas?

Cheers.

Re: Glass Reflection Problem

Posted: Tue Jun 13, 2017 12:31 am
by ChrisAngelius
I literally am doing a project for an OLED tv right now.
My solution was rather than using a glass material, was to use a glossy material for the screen content.

Well rather a mixed material, Diffuse with my screen content loaded into a blackbody emission and glossy with the same texture loaded into the diffuse. Saves rendering time since it doesn't need to worry about the refractions, and still reflects the lights in the scene.

Re: Glass Reflection Problem

Posted: Tue Jun 13, 2017 1:38 am
by Teddi
Thanks Chris.

In your model is there a gap between the glass and the screen?

In mine there is, so I've got a diffuse material with an image sequence as the diffuse texture and the same image sequence as a texture emission so the screen produces some light.

Then maybe a 1-2mm above that is the glass (I think it's actually more of a perspex or synthetic material.)

If I'm understanding your method correctly I'm not sure it'll work for my model, I may that wrong though.

Re: Glass Reflection Problem

Posted: Wed Jun 14, 2017 2:27 am
by ChrisAngelius
If I understand you correctly, you have a gap between the glass and your screen? The glass on my model rests against the screen, in fact they're likely intersecting slightly. Rather then place the screencontent on a place behind the glass, I've just used the glass for the screen content, that way it emits light properly and I don't have to worry about the refraction behaving unexpectedly.

Re: Glass Reflection Problem

Posted: Wed Jun 14, 2017 2:55 pm
by DinoMuhic
They need to intersect a bit. Gap is wrong and its likely why you are getting another bounce there.

Re: Glass Reflection Problem

Posted: Wed Jun 14, 2017 6:00 pm
by RSgraphics
You should check out this thread. I asked about the best way to make a realistic iPhone Screen and got some great suggestions. It's very realistic and there's no issue with the screen reflecting on the glass.

viewtopic.php?f=30&t=61746

Edit: My suggestion to check out that thread is valid. However, in this thread, DinoMuhic says you SHOULD intersect the geometry just a bit. Im a newbie so go with what he says, I just know that it worked for my situation. Also, in the thread i reference, niestudio posted a downloadable file with a perfect working example, so make sure you check it out.

Re: Glass Reflection Problem

Posted: Wed Jun 14, 2017 8:32 pm
by Teddi
Thanks a lot everyone.

Not had time to look at this model as had other work on but downloaded the zip of the iPhone from the other thread and will have a look at it and the stuff written here over the next day or two.

Re: Glass Reflection Problem

Posted: Sat Jun 17, 2017 2:14 pm
by Teddi
Thanks everyone.

Got the problem sorted (I think), I've just used the glass from the iPhone model posted in that other thread.

It seems to have got rid of the refraction/second-image problem but still shows reflections.

I was using a Pixel Lab glass before which I couldn't find a way of editing to get rid of the refraction.