Glass behind glass renders dark

[djwaterman]

I have a car headlight that sits behind another glass layer. It either darkens the headlight too much or renders black. I've tried a lot of different things but I still haven't been able to pin it down. Has anyone else uncounted something similar?

[t.petrov]

Have you tried to increase the Max depth attribute in the reflection/refraction roll-out of you VRayMtl?

[griml0ck]

It could be that you don't have a texture connected to the refraction slot in the environments settings in render settings. And remember to check all your normals. After that it should be fine. If you still feel it's too dark you could uncheck "visible to GI" on the glass objects.

[djwaterman]

I had it set to 10, then tried 150, no difference so I put it back to 10. Here is what I'm seeing.



I would like it to look more like the first image but with the glass cover in place. Can you exclude an object from the GI calculation? Perhaps that would help.

[djwaterman]

It could be that you don't have a texture connected to the refraction slot in the environments settings in render settings. And remember to check all your normals. After that it should be fine. If you still feel it's too dark you could uncheck "visible to GI" on the glass objects.

Okay, I didn't see your answer until after I posted the previous.

[djwaterman]

Yeah, I have textures in all those slots. The normals appear to be correct but I no longer trust them, I may have to remake the glass. I'm trying to find the visible to GI checkbox.

[djwaterman]

Found it and trying it out.

[naik]

Maybe you should check your refraction settings in your glas cover shader.
Try to increase your refraction color to 0.98 ( almost white )
Also check your IOR value. Try decreasing it to almost 1
The "Reflection on backside" option inside your shader can help too.

regards
naik

[griml0ck]

Select your cover glass surface and make a vray object property node, uncheck the visible to GI checkbox. Problem solved, have had this one before also