Indeed, I confirm that the bug appeared when the project was reopened just after the 5.1.1 update without modification.
I tried today with a new one and the artifacts with Lumen also appear…
While waiting to find a solution, how can I do to find a correct level of quality? reinstall 5.1? how?
This problem also exists on translucent objects. Also, neither volume fog nor translucency can accept GI, even if TranslucencyVolume is turned off.
Is there a cvar for controlling detail tracing vs global tracing? I was thinking this would be a good option to have in graphics menus for being able to scale lumen quality.
Not sure if this will be helpful to anyone but I’ve noticed that larger meshes (including ones rescaled to be big) will exhibit significant leaking in the Lumen scene. Guessing there must be some limit to the texel density.
In this case I have a 1 meter thick wall and a large floor mesh, when the floor mesh gets to be larger than 40m the leaking can’t be hidden anymore. So if you have thinner walls you’ll probably want to break your floors up into more pieces.
Screen traces will try to cover over the mismatch but you’ll get pools of light in areas where the screen traces fall back to the surface cache. Really annoying in areas you want to be dark.
If anyone has a better solution than just “don’t do that”, I’d be grateful to hear it.
What happens if instead of scaling it you put a 40+m mesh? it still leaks?
Hi, what we should do if the lumen scene is not close to the actual scene? where would be the problem and what would be the steps to follow?
Yep
So I tested it my self, and didn’t get the same results, well not exactly, it looks like from 18x scaling it starts to leak but as you can see in the images the mesh have to be veeery large to start to leak.
How large is it at 18x scale?
Are there any plans to expand Lumen to provide functionality similar to NVIDIA RTXDI?
There was, of a sort. A feature called ‘Lumen Direct Lighting’ was created when 5.1 was in development, and my understanding is that it basically uses lumen’s screenprobegather to handle all direct lighting. In the original CL, their numbers showed LDL to be significantly cheaper than VSMS, DF shadows, and even traditional shadowmaps in some cases, but the quality was abysmal. Because it only worked with SWRT, you got blobby, temporally-unstable shadowing that tended to miss important features, but it was dirt-cheap.
As of 5.1.1, lumen direct lighting is nonfunctional (just tested), but the command still exists:
The original mesh is 700x960 so 18x is: 12600x17280 or 126x172,8 meters, so way more than 40 meters
How thick are your walls? And are you using default Lumen settings?
Thanks! I really hope it one day measures up to RTXDI, which seems to be quite good in demos and in Cyberpunk.
20cm and yes default settings
Oh great thread to pop back up!
Just posted this a few days ago
Shadow/Reflection differences M1 Mac/PC - Development / Rendering - Epic Developer Community Forums (unrealengine.com)
I agree with you that a good sampled lighting solution would be very valuable for increasing lighting quality. That being said, I did get the chance to actually try RTXDI in NVRTX 5.0, and I found the quality to be lacking (made a post about it somewhere). If they’ve improved some of the quality in 5.1, then it may be something you should check out.
Well thats weird 
No idea what could explain the difference
Exponential height fog, fog inscattering color adds additional skylight which ruins scene. Either i have to have black fog inscattering color with bad horizon fog and good lighting or the otherway around. This completely ruins either scene or horizon look. there should be a setting to make Fog inscattering color not add additional skylight or affect scene lighting at all. Below are some examples the problems associated with this.
Seems more like a problem with your setup honestly. Are you using the SkyAtmosphere system?
