sss through glass

[Mnietek2707]

Is there any way to get proper SSS/translucency seen through glass?
I always get some kind of darkening when object with translucency or SSS touches glass.


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sorry for my English

[georgi.zhekov]

Do you have affect shadows turned on for your glass?

[Mnietek2707]

I tried every option: affect shadow OFF and ON, I also tried turning off shadow casting for glass object. Without success...

I realised that turning OFF "visible to GI" for glass object helps in case of FastSSS material (but there is dark line at the border between sss object inside and outside of glass). GI is set to BF/light cache.
During lightcache calculation there is no darkening even with "visible to GI" set to ON. Darkening appears on final rendering.

In case of VRayMtl with translucency no matter what I do there is darkening.
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sorry for my English

[Mnietek2707]

Further investigation...
Below comparison: visible part of objects are lit by indirect illumination (light is behind of glass) vs direct illumination.
Inside of glass is object with no translucency or refraction.
In first case there is strange darkening... Something is wrong here I think...

[vlado]

Can you post just that part of your scene?

Best regards,
Vlado

[Mnietek2707]

max file from previous post (max 2015): LIGHT01.zip

[tashko.zashev]

Thanks for attaching the file.

Activating the Reflective GI caustics will help in this case. Here is the final render result :
*) the original setup >


*) SSS2 material >

[Mnietek2707]

Thank you!

[Mnietek2707]

Sorry but I have problems with this again.
Previously I didn't have to turn the "Reflective GI caustics" on. I just turned the "visible to GI" off for the glass and used VrayMtl eith translucency. This worked.
I'd like to use VrayFastSSS2 now but regretfully everything that is visible through the glass is much darker (and noisier) than without the glass. Turning the "Reflective GI caustics" on does not help.

Renders and the trouble scene:



Max file: fastSSS2 problem.zip

[tsvetan.geshev]

Hello,

If you turn on Affect shadows in this last scene, that you have posted the result will be very similar to the original liquid.
Maybe you have forgot to check this?

[Deflaminis]

Just for personal knowledge, why does the reflective caustics fix the issue? Is it because those caustics travel through the volume brightening it?

[Svetlozar Draganov]

Just for personal knowledge, why does the reflective caustics fix the issue? Is it because those caustics travel through the volume brightening it?

It is because the indirect illumination of the SSS material is not being reflected by the glass object and as a result the SSS appears darker.