Regarding Lumen in “Preview 1”, its fine, except for… you know what im going to say now: Trees, Foliage etc.
Will upload your project somewhere and send it to me? The trees are way darker than I’d expect with Lumen. We have over shadowing problems, but nothing that should make the outer leaves dark too.
GKan just sent me his foliage scene and now we are working on reducing the over-shadowing.
Lumen supporting Subsurface Shading Model was in Preview1, but not Two Sided Foliage. However, that generally only brightens up the trees a little bit, it doesn’t fix the dark core problem.
Yes, subsurface is actually broken again:
Is the sun hitting the other side of the Subsurface material (the skylight) and scattering through to the bottom side, and that’s what you expect to bounce lighting through Lumen GI? I don’t think we have ever intentionally supported that, so it’s a surprise that it worked before. It’s probably something we can add though.