Double Glazing render times

[KC149]

Hi guys, new to the forums but I've been using corona for a little over a year now. In an effort to make my scenes more realistic I've tried to use double glazed glass where applicable but on the exact same render using the same workstation the render times have increased from 14 hours for 50 passes to a little over 24 hours for the same number of passes. I obviously expected some increase in render time but that was well above what I was expecting. So I wanted to see if anyone on here has experienced this and what you awesome guys have done to get around this?

[agentdark45]

Yep its a common issue and I've noticed the same thing. One workaround is to use one sided planes (or several of them spaced apart) instead of thick geometry for the glass in the windows, and then make sure to tick the "thin" option in the glass material. This will obviously get rid of refraction but it massively reduces render times.

[maru]

What Agentdark said - use thin glass where possible. Also, it seems that there is a problem with rendering refractive objects from up close in the newest versions of Corona (maybe it was present all the time...?). We already have some ideas how to solve this.