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Octane for Unreal - No light passing through glass

Posted: Sat Jan 01, 2022 11:03 pm
by Ferdinand13
Hello,

I've got an issue using Octane in Unreal 5.0. For some reason, Octane won't send light through a glass window. Have a look at the image below. There is supposed to be light coming through this translucent material and Unreal/Lumen pick it up properly. But for some reason, Octane doesn't seem to "see" the glass material.
OctaneUE_NoLightsThroughWindow.png
Any ideas what could be going wrong? Thanks for letting me know :)

Re: Octane for Unreal - No light passing through glass

Posted: Sun Jan 02, 2022 6:03 pm
by Ferdinand13
I take this one back. Activating the "Fake Shadows" option in the Octane Material settings did the trick :roll:

Re: Octane for Unreal - No light passing through glass

Posted: Mon Jan 03, 2022 12:54 pm
by ChrisHekman
For glass and other transparent materials it is often better to use octane materials, as the conversion is not always great depending on how the unreal material is set up.
Also, for glass it is often better to set the kernel to the Path Tracing kernel.

Re: Octane for Unreal - No light passing through glass

Posted: Mon Jan 03, 2022 1:56 pm
by Ferdinand13
Thanks Chris, yes I did that. The "Fake Shadows" option in conjunction with the Kernel set to Path Tracing does the trick.

Now my only issue is that the refractions inside the game engine look strange at acute angles, but that's a UE question I guess :D

It seems though as if Octane prefers refractive geo with thickness, while - according to all the tutorials I've watched so far - UE is happier with a one sided polygon instead. Just in case you've got thoughts on this ;)