I have a question regarding GI and transparent materials.
Is global illumination unable to pass through transparent surfaces?
As shown in the image below, when there's a glass panel in the middle, the areas behind it become significantly darker.
After checking the AOVs, I noticed that the direct diffuse looks almost the same, but the indirect diffuse appears extremely dark—as if it can't pass through the glass at all.
Of course, enabling caustics helps to some extent, but in more complex scenes, it introduces a lot of noise and drastically increases render times, making it impractical.
I'm mainly using V-Ray, and I haven't encountered this issue there—indirect light passes through glass much more naturally.
Is there a way to achieve a similar result?