Hi Team!
I would want to leave you some feedback for Lumen and Nanite, after trying both for a real development case (Unreal Engine 5, Lumen & Nanite techdemo):
-
For high detailed meshes, would be great to be able to use some kind of high detailed collision, but Use complex collision as simple is unusable, as it seems to use the highest Nanite “LOD” for it, and kills the framerate. (Would be nice using a less polygonated Nanite fallback, or even being able to adjust the fallback “polygon level” in a more custom way).
-
Make static meshes to cast “two sided” shadows. When rendering, materials are only shown in one face of a polygon for performance purposes; that makes sense, but those objects are usually placed as “limits” of a scene, and may have lights behind them. For me, at least, seems obvious that they should cast shadows, as RT shadows does.
VSM shadows:
Ray traced shadows:
So, I was using RT shadows to solve this.
- Please, make Nanite “compatible” with ray traced shadows:
There are some tricky adjustments over the internet, but all of them are quite unapropiate, as all cause other kind of noticeable, weird results (read my post here, about those tricks: City sample vehicles - weird shadows - #8 by Miguel1900). I needed to use a combination of them to get the best possible result, wasting a lot of time making the tests.
- (Again) SMs should cast Lumen GI in both directions (something like “two sided”). Another option would be to close all Megascans static meshes, even with a very basic shape on that “rear” side and even with a second material ID, so we would just put a plain colored shader on it, to avoid this kind of things:
I needed to place boxes behind those open static meshes, to occlude GI passing through:
And I think that was all, if I’m not missing something. I hope you shareyour thoughts and you like this.
Thank you and best regards!