I made a few models and have light bleeding, or it’s a shadow problem; not sure tbh. Are my models too thin perhaps? UE5 Preview, Virtual Shadowmaps
Have you tried increasing the meshes bounds scale to see if that might help?
thank you for the reply, will give it a try EDIT* no effect
If it’s too small, Lumen will only trace against it in screen-space (there’s a setting in the PP volume to control object size for the traces, but it gets expensive FAST. If you’re using VSMs, they can be kinda strange, but select RT shadows and some of the artifacts should go away. IMHO, it looks more like a shadowing problem than a Lumen problem, but adjust the settings and see what you find.
If worst comes to worse, and this is just a setpiece without taking place in a larger game, just scale everything up in size. Lumen is biased towards player-scale objects, so just making it bigger should help increase the quality.
unfortunately I need to keep the scale. Non of the options made a difference.
Hmm, that’s interesting. Have you tried ‘FreezeRendering’ and seen if it might be a culling issue?
How do I do that, thanks
enter it as a CVar into the console and see what happens.
Enter it when you’re close and the image looks fine, and back out. That will let you know if it’s a culling issue, assuming the object is non-nanite.
It is a ninite object
I see. In that case, this will get interesting. Nanite objects have a custom cocktail of streaming and LOD rules that sometimes behave very strangely with objects (such as a wall changing its’ tile pattern the further away you get, which I’ve experienced.
Are you using hardware or software ray tracing?
Software raytracing
In that case, check the resolution of the mesh distance field that represents the she shell. Since it’s a lot of thin geometry, it could easily be light-leaking from the SDF’s volume texture being too low-res to represent it. set the mesh distance field resolution in the settings to 2.0 or higher, but this does come with a memory cost.
Either that, or use HW ray tracing if available. Either way, it should help.
Unfortunately no change
As soon as it touches the landscape it happens. If the poly count is too high and dense perhaps this could be the cause? I tried scaling it up and the problem goes away, but it’s the equivalent size of a bathtub
I’m not sure that would be the case. If it’s software, then all indirect lighting is solved with the SDFs, which are created out of the mesh, but aren’t the same thing as the mesh. If it’s hardware, it would automatically generate a proxy mesh with a lower polycount, so unless the proxy mesh and the nanite mesh are very different, there shouldn’t be a problem.
My guess? If you’re working with the preview build and have lumen with landscape, there tend to be some relatively strong artifacting if you intersect with terrain. The reasons for this are very complicated and I only loosely understand it, but the landscape traces are offset by a certain amount to avoid self-intersection, and there’s a possibility that your small mesh sits inside of that offset, causing the trace to avoid part of the mesh. It would get worse as you get further out because the landscape would be tesselating to a lower LOD, and screen traces would catch less and less of the mesh to hide the artifacting.
Essentially? I’m not sure you’ll be able to intersect the mesh with terrain on this current version of lumen without problems. That being said, I also don’t have all the information, so if I learn more, I might be able to help.
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Thank you so much jblackwell. I greatly appreciate it.
By all means, I’m happy to help if I can. Best of luck with your project.
So I tried hardware ray tracing and it seemed to correct the problem, though it totally tanked my fps on my AMD card, and everything in my scene has black splotches all over it from ray traced shadows. Still the performance hit is too much for this to be a solution and it seems like correcting one problem just created another…
