It begins :D
For context, this is - was - my vore day picture back in 2018, and after a few people brought it up as a favorite of theirs, it's now the first scene I've decided to go ahead and re-render on the new computer. Rendered in Iray, compared to the original being done in 3Delight, and the difference is pretty huge! I had actually thought it might not be so noticeable, but I was quite wrong.

(gif: old to new renders)
There's some changes to the scene beyond just plopping it into the new software and pressing "render", but I tried to keep as much of it the same as I could! The sign is gone, that much is obvious; tongue pose is also adjusted, taking advantage of DS4's ability to apply some collision simulation and let it *squish*. The rest is all in the materials settings; changing all of the shaders from 3Delight to Iray, experimenting with glossiness and displacement and trying to account for everything that changes when going from a biased renderer to a physically-based one. (Including a few frustrations, since physically-based is *very* good at highlighting anything that's wrong with your models, and does lack a few of the less-realistic-but-handy features of a biased render engine.)
----
In any case, I'm quite happy with the result. I don't know how long my old, original render took, but it was probably in the ballpark of an hour; the new one, rendered at close to 4k resolution, was done in just over 15 minutes. That improvement is due to the computer not the render engine - old computer would have never managed it at all - but it's a huge bit of confidence to know that now, I can render scenes of this detail in just a fraction of the time my old renders would have taken. ^^
There's more to come, soon! Hopefully soon. This was a bit tricky to work with, but I have a decent grasp on how the shaders and renderer work now, and I have a couple other pictures I'd like to revisit in the same manner as this one, so look forward to those!