To my knowledge, cards wouldn’t necessarily be a massive limiter when it comes to compute performance, although they do have other implications.
Cards let lumen cache expensive lighting behavior over multiple frames, and they do this by packing all the cards into a big atlas texture stored on the GPU. As you move around a scene, cards pop in and out so that the area around you always has coverage, up to certain user-defined limits. For very complicated objects, they inherently need more cards to get complete coverage, so they can be more expensive in how much cache real estate they take up.
So theoretically, if your scene is filled with many different opjects that would all be vying for surface cache coverage, there may be an advantage to reducing how many cards each object needs, but with how simple your objects are I’d be somewhat surprised if it was a big perf problem.
I see. In that case, I think you’d be picking what enemy you’d want to battle, lightmap UV scenes or lumen capture discontinuities. One might be easier than the other, but it’s up to your needs/discretion. If the cubemap can be prefiltered, the lumen approach might work better, because the fine details will be obscured anyways.
Sorry for the late answer. The PPV settings vary from shot to shot. They also do not affect the reflection issue. We do go as high with the settings there as possible until scene performance becomes very bad or we cant see any visual difference anymore. The issue seems to be caused be the bend shape of the mesh.
Its definitely possible and I’ve experimented with it by building using these instructions. I’d also really like to see a toggle in capture components with stock UE. Like you said, the cost of having two lumen scenes is not really realistic so it’s only really useful for saving cubemaps. I used it for generating fake secondary bounce reflection maps that otherwise wouldn’t integrate well within a lumen lit scene.
We have our wish granted as of 5.1 - and even better - with customizable surface cache resolution so performance won’t be as dire as feared.
Edit: Still not available on the cube capture though unless I missed something - I feel it should be accessible on all capture components by default. But still a good improvement regardless.
Hi, does lumen have bugs in epic and cinematic scalabilities in unreal engine 5.1? Lumen perfectly lights up “lit particles” under shadows in high scalability (similar to unreal engine 5.0 in all scalability settings) but it doesn’t in epic and cinematic!
The fact that first, you need to set it to cinematic and then set it back to high in order to make it work (if you set it to high from epic it doesn’t!) makes me feel like it’s not intentional and maybe a bug. It doesn’t look to be limited to particles either, the entire scene’s lighting changes!
Hello everyone!
I’ve been looking all over the internet for a solution to a peculiar issue I keep having whenever I render a footage any environment in Unreal Engine. In close proximity to scene elements, my camera generates green noise and distorted color flares. Can anybody provide insight on what may be triggering this?
That is most likely an issue with your post process configuration settings, it seems to resemble UE’s lens flare and glare settings. I’d start by disabling their functionality in the PPvolume and see if that resolves it.
Any chance we’ll see lumen refraction for translucency at some point? Screen Space Refraction leaves a lot to be desired and RT doesn’t integrate well in lumen scenes. Not sure if there’s a technical reason we don’t have it, but it seems like it should be feasible now that we have high quality translucent reflections.
Why is the light of the sky reflected on the floor in my room? This place has no window. And it has something to do with these cabinets. The walls and ceiling are thick (about 30 cm) as I struggled with light leaks in concave corners.
It turns out to get rid of these reflections by increasing the distance for detailed reflections in CVar (r.Lumen.TraceMeshSDFs.TraceDistance) to 800 (I think centimeters, like the width of the room in this place)
Display mode on screenshots Detail Lighting.
These reflections are disabled when changing “Software Ray Tracing Mode” to “Global Tracing”.
Is there any proper way to get rid of this? Not as expensive as the quality of the reflections. The cube behind the wall also helps, this is the cheapest at the moment, but if I want to make an exterior, then this is also not an option.
I am new to UE.
That problem is interesting to me. I don’t see a reason you should be getting leaking given the way you’ve designed your scene, but I’d start by looking at the surface cache visualization and seeing if your objects aren’t showing up, that should give you an indication of some of the behavior you’re seeing.
I got to hear a bit about some of the rendering team’s next objectives, and while I could be wrong or misunderstanding what I was told, I think it might just be not as high a priority for them. SS refractions do leave a lot to be desired, but not having them doesn’t create problematic leaking like a lack of reflections might. I believe one of the lumen team’s big priorities now are improving rough and glossy reflection quality, which is a definitely big pain point.
This is some technical speculation, but it could also be down to the challenge and expense of effective RT refraction. Transparent reflections ‘just’ mean drawing another gbuffer with transparent surface information, tracing rays on it, and then doing it again while ignoring the glass. Refraction could mean more expensive calculations and holding more scene information in memory, and I’m not sure how that would fit with lumen’s more cache-friendly nature.
Yes they are. And given that you’re seeing coverage in the area when you’re experiencing leaking, it might just be a lumen ray length issue, which can essentially only be fixed by either increasing the length or creating an HLOD for your scene, a low resolution scene representation that’s cheaper to ray-trace against.
In that case, you may be out of luck. HLOD’s ‘far-field’ ray tracing only works with hardware ray-tracing, otherwise your traces are essentially confined to 800 meters or less.
I am trying to find any information on that issue, without success.
So since 5.1 we are allowed to use reflection on translucent material; Yay!
But is there a way to make the high quality reflection on translucent materials to get softer with the roughness value ? It does work as intended with an opaque material.
Both have the same value (roughness, metallic, albedo etc…) except the one on the left is Translucent and the one on the right is Opaque
Only speculating myself, but in theory I would think that tracing a ray for refraction would be more or less the same as tracing one, you just go a different direction. Obviously there’s more to it than that but the scene data is there.
