Non transparent sections of glass

#1

Hi, New to this forum and fairly new to C4D.

I have a glass material within HDRI studio rig. The glass is part of a test tube made with circles and ‘loft’ nurbs.
Getting some great results but have an issue with the bends and ends on the glass. These areas (marked on image) are grey, reflective but not really transparent. I have messed about with the ray/reflect/shadow depth but can’t achieve the right result. I thought it might have to do with there being no other objects in the scene, as at the moment it’s purely lit and reflecting off of the HDRI rig.
But If I add some objects behind it, the same problem occurs. Could this just be the physical ‘behaviour’ of glass in this environment? Seems weird. Any ideas? Thanks!!!

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Screenshot 2020-01-29 at 11.34.30.jpg4456x2586 1.15 MB

#2

Experiment with these options under Refraction Index:

Total Internal Reflection
Exit Reflections
Fresnel Reflectivity

I think the problem is the Total Internal Reflection BUT read carefully the manual to learn what those options mean because the play a significant part on a real world glass material.

In reality I don’t think that laboratory test tubes are made of ordinary glass. Even if your Refraction Index is correct you might have gotten the tube’s scale wrong and the thickness of the tube is too great.

#3

In addition to the above reply …

  • use a prebuilt shader like bangi glass 004
    That should get you something like this using the GSG set

TT
TT.png232x523 166 KB

#4

Hi Demis,

Thanks for the tips, will go and try them. I’ll check out the TIR too. Nice one! J

#5

Hi Vid2k2, interesting, I’ll certainly try a prebuilt shader! Thanks, J