Material renders black through two layers of glass

[vincent architect]

Hi guys,

First time post. I'm designing an office building and i have trouble rendering a metallic air duct. I never had this kind of problem before but it seems that when seen behind two layers of glass, this specific material turns out black but every other material is rendering fine. If i go inside the glass box and look at it through only one layer of glass, the air duct renders better it seems. I don't know if the problem comes from the glass material or the metal material. I've attached pictures of the renders and of the materials propreties. Thank you for helping !

Vincent

[Peter.Chaushev]

Hello, Vincent,

Simply increase the galvanized metal's Reflection Max Depth parameter value to 5 (or higher) and it should appear correctly.
The problem with your scene is due to the limit on how many times the metal's reflection is traced. The reflection bounces were capped at 3, therefore after the third surface is passed, the reflection is not displayed. Here's an illustration to help you understand how this works:



Keep in mind the Max Trace Depth setting can be found in Raytrace (advanced view) > Optimizations. This global override is always enabled during Interactive rendering. In Production, it is disabled, meaning each material's individual trace depth values are in effect.
Let me know if you have any further questions.

Kind regards,
Peter

[vincent architect]

Hi Peter,

Thank you very much for the very clear explaination !

I was trying to increase the Refraction Max Depth instead of the Reflection Max Depth.

Problem solved thanks again !

Regards,
Vincent