Did The Lighting Recently Change In Daz?

IceDragonArt

So, its been awhile and I keep running into weird stuff.  Like, some light sets don't work anymore?  Or, they don't work in Iray preview but work in the render?  (which is less than helpful if I am trying out dozens of combos)  Maybe its just me... So in Daz 4.10 the lights I am testing don't work in the iray preview but work just fine when actually rendering.  As I said, less than helpful and far too time consuming.  in 4.24 they are barely visible in the iray preview and while they do kind of work when rendering, its at a much reduced illumination and there isn't any way to crank them up that I can see.  Do I just need to find other lights or maybe i just need to spend some serious time and do my own setups to save?

Matt_Castle

A change was made to Iray some time ago (Late 2021/DS 4.16, I believe) that fixed unintended behaviour regarding emissive mesh shaders.

This behaviour was however often being exploited for "Ghost Lights" that could illuminate a scene without themselves being visible, so sets and light sets that predate the change may no longer work as expected.

(A bit of an annoyance, but Nvidia did actually incorporate some alternative methods for "invisible lighting", and those can actually be used for some pretty cool tricks)

Taoz

They fixed a bug affecting mesh lights at some point, which means that for mesh lights created before that (which technically were bugged also to compensate for the issue) you must change Luminance under Emissions to make them work again (some affected mesh light products may have been updated since, I don't know).  As for other changes I'm not sure, but Iray has been updated a few times recently AFAIK, though I'm not sure about the details and whether they affect older light products.

IceDragonArt

okay thanks!  I've been gone since roughly late 2019 to early 2020 so Ive missed a lot lol.  Just trying to get back up to speed