Lumen in UE5: Let there be light! | Unreal Engine

Lumen is the result of years of research at Epic to bring real-time Global Illumination and reflections to Unreal Engine. In this video, we'll show what it is, talk about its features, and walk you through a high-level overview of how it works.

[@RasmusSchultz]

I've been following game tech since the 80s, and this (along with Nanite) is definitely one of the biggest breakthroughs I've seen. I wonder if we'll ever get rid of the "creeping" shadows and reflections that kind of trail after camera and object movements though? I'm not sure everyone even notices, but it's really obvious to me for some reason. Still, the environments look absolutely gorgeous, and the fact that lighting can update when objects move around at all, is mind-blowing 😄

[@veedrac]

Absolutely we will; some of the very recent research that has stemmed from ReSTIR is showing how to do nearly perceptually unbiased illumination in a lot of cases that have been extremely hard to handle. We don't have all the pieces quite yet, but I think anyone smart and familiar with this part of the literature can imagine quite easily how to complete the picture, so to speak.

[@cerebralm]

The "creeping" (technically usually called "ghosting") is from the feedback. Feedback is used to reduce the amount of calculation done per frame to hit framerate. The more powerful the GPU, the more calculations can be done in a single frame and the less feedback is needed, so as graphics hardware gets better the ghosting will get less intense. Of course, there will probably also be improvements in ways to mask "changed" areas for higher priority calculation or dumping of history. EDIT: also note that since the feedback is done offscreen, ghosting is only visible during major lighting changes. That means it won't be noticeable in most real-world use cases, as very dramatic lighting changes are usually only done in conjunction with other effects like particles or other setpieces. The exception is the reflections because they are view-dependant, but of course, reflections in games have always been a bit janky. :P

[@RasmusSchultz]

@@cerebralm my only point is this approach will not work for every use case. I just played Little Nightmares 2 last week, and there is a lot of gameplay in dark rooms where the character carries and aims a flashlight - the real time shadows are critical to game play, and it wouldn't have worked with any delay at all. Of course, for mostly static scenes, and for things like daytime lighting, Lumen is absolutely brilliant though. 🙂

[@ChaojianZhang]

Also it seemed the shadows are wobbling around even for a stable camera position?

[@Silvermahdi]

The truth of what you said was proved by the release of The Matrix tech demo

[@darkscorpion6534]

My Uncle was an early 2000s 3dCAD CGI artist. He passed away about 12 years ago. Seeing how far CGI and 3DCAD has gone in the past 15+ years would blow his mind!!!!!!!!!!

[@VirtuLlama]

Lumen is the game changer for all of us. Thanks for that 😅

[@lordkiller977]

Thanks Epic for all you do for us artist and developers.

[@STVinMotion]

This is an amazing technology and the presentation is really clear and helpful. Really appreciate the effort you puth into it, Paulo. So stocked about the emissive materials 😍

[@Spamkromite]

One of the best things to happen to game-developing science in decades. Oh wow, the tips for illumination, I knew none of them. I shall apply them to my workflow!

[@dadandme]

I love using UE5 and especially Lumen! The Lumen team did a terrific job 👌

[@MonsterJuiced]

Thank you so much to each of you for all of your hard work on this tech. I really can't wait for all of the oversaturated 80's neon metropolises to start cropping up.

[@fleurbird]

First i like to say thanks to the gods at the lumen team. This is mind blowing guys! Secondly: This was a very good presentation. No nonsense. Honnest. Informational. Not to long. Not to short.

[@wbhtrb3008]

There is one god

[@CP-Mohammed]

@@wbhtrb3008 good for you

[@cvspvr]

​@@wbhtrb3008and his name is brian karis from the unreal engine development team

[@JazerMedia]

I can already see improvements to Lumen since they first showed it off. Interior scenes like the one at 13:48 used to be a bit noisy due to the challenging lighting circumstances.

[@antuAnoro]

Lumen is insane. So effective while resource saving. You guys are smart, good job!

[@sergiokaminotanjo]

short simple and straight to the point, even a common gamer like myself can understand the magnitud and implications of this new breakthrough technology. This is a complete game changer and it will change game development forever by making it easier, faster and better

[@Glowbox3D]

Nice video. I've been using UE5 and Lumens for a few months now, and I'm loving it. There are a lot of settings (and even console commands I guess) that improve the quality, and it's all very early-access, but I'm digging it so far. Thanks!

[@m2virtual_com]

un par un par

[@DirkTeucher]

"No Harry no, don't look at the light" - Bug ... "I can't help it it's so beautiful." - Harry

[@Moritz19081980]

As someone who started gaming in the 80s your work brings tears of joy in my eyes.

[@daveD0607]

Someone did a great job in recalling all those robots from the city.

[@mogmaximus]

Epic hired everyone with the highest score in that game to help them out

[@RayTracingRevolution]

super exciting stuff, I can't wait for RTGI to be common in games everywhere

[@iljavieten687]

ABSOLUTELY PHENOMENAL!!! This truly is a new step towards more realism and adds a lot if drama to every scene...GREAT JOB!!!👍🏻👍🏻👍🏻😃😃😃

[@Eroktic]

Different strokes for different folks... Lumen is perfect for certain things and I can't wait to see the creations in 2023 :)

[@belvss896]

Wow, you around here, representing the great KALASHNIKOV? SKRA

[@IPpainting]

Yeah i make VR games at work and all this doesnt benefit me at all sadly

[@boukm3n]

SKRAAAAÄAAAAA

[@lhmsc]

Great! Would be nice to have an hybrid approach using planar reflection for perfect mirrors. Right now the results from Lumen alone are not that great even with hardware acceleration. Also a solution for translucency would be great, but I believe it will be solved by the time we get the full release. Lumen is probably the most exciting new technology I've come across in the past years.

[@jakubjodlowski2768]

Magnificent Tech and Video. Thank you Epic

[@michael14876]

I can see this working really well for Architecture.

[@Zdrthn]

Thx, we really need a tutorial like this more than a group talking.

[@TheOriginalDarkGlitch]

Emissive materials acting as lights without building lighting? What a time to be alive 😁

[@thronosstudios]

I love how Lumen causes even the arrows and indicators for scaling, rotating and moving objects to affect the scene also 😂😂😂😂😂. Brilliant (no pun intended)

[@mogmaximus]

that was not a pun, no one is laughing

[@thronosstudios]

@@mogmaximus Lumen + brilliant... I'd say that's a pun since we're talking about lighting here. Pretty lame that I have to explain the pun to you. Also, I laughed... so you're wrong twice.

[@King-mj2bn]

@@thronosstudios No we all see what you were going for. It just wasn't a good pun. If I asked you to describe the sun in one word and you said brilliant, I'd slap you in the face.

[@jahormaksimau1597]

This is magic.Thank you!

[@rw6399]

I like how the transform gimbal is considered in the lumen buffer so it glows into the scene. I know it's probably an unintended consequence but please keep it in.

[@fabianoperes2155]

I also noticed this. It looks so nice.

[@sams_3d_stuff]

same here.

[@newsonomamashine]

God no, just no, there´s no reason why that shuld happen, and sometimes that annoying ghost gi form the gizmo stays there even if you deselect the object, JUST NO.

[@Sciontidesign]

Thank you for this great video and for the mention :) oh my correct artstation is pscionti

[@Bob3D2000]

That was excellent, thank you. :D

[@christianwurm4022]

Great Improvements for Software Ray Tracing! I wonder if you can use this technique like Surface Cache and Mesh Distance Fields for hardware ray tracing as well? It probably would be a huge performance improvement and really appreciate because Hardware Ray Tracing is still so expensive.

[@Eternal_23]

Thank you guys for lumen

[@spacepirate9882]

My only hope is that landscape, foliage and subsurface scattering) support by Lumen is on the top of the roadmap. Actually, only urban or full static mesh scenes looks good with lumen.

[@Jafoss]

Edit: Ignore this I was misconceiving. You're mistaken. These are all supported by Lumen, but not Nanite. But that brings me to a common misconception. Nanite is *not* a global system. It is enabled per mesh, meaning that anything that requires translucency or other effects not supported by Nanite, can use the traditional LOD system instead and it will render just fine.

[@spacepirate9882]

@@Jafoss No, actually there's no realtime GI from landscape and foliage because they don't have surface cache. Also subsurface scattering is not showing once you enable Lumen. GI has nothing to do with nanite which is about geometry.

[@Jafoss]

@@spacepirate9882 Ah I see now. I see a lot of people misconceiving the translucency and foliage limitation of Nanite with Lumen, and I wasn't aware of the lack of surface caching with landscape and foliage or the SSS error, so I thought you were with the crowd. Though from what I recall from one of my own projects SSS was working for me with Lumen enabled, unless it's a bug that happened in the new hotfix.

[@spacepirate9882]

@@Jafoss I still don't get why you're talking about Nanite (virtual geometry) while I'm talking about Lumen (realtime global illumination). Nanite and Lumen are two different things, they are not related to each other in any way. You can use Lumen without using Nanite at all.

[@EeVeE3D]

Lumen is really amazing...

[@danidaniel1161]

Parabéns, Paulo, ver um brasileiro a frente desse tipo de coisa nos enche de orgulho!

[@MarkOakleyComics]

Cool. -As a cartoonist, one of the Grand Principles I lean on when it comes to shadows is that, *"People are wired with very low resolution cognition regarding shadow play. That means you can use very broad stroke approximations, and so long as they stay within the bounds of very basic physics, nobody is going to notice or care."* So UE5 is basically doing the same thing, taking a low-resolution solution and layering it on top of high-cognition granular detail. In retrospect, it's a little surprising it took so long to implement, but that's how it goes with lots of great ideas which seem obvious only once they're in place. Great job either way. The real-time effects are absolutely stunning!

[@mrbogdanoff9233]

This is a game changer, literally, I'm talking computer games

[@irecordwithaphone1856]

This is incredible

[@sams_3d_stuff]

Lumen is amazing!

[@aresaurelian]

Good presentation. I approve. Thank you.

[@iehudim]

Salute from southern Brasil !

[@Kineticartist]

absolutely brilliant

[@victorblanchard7774]

Lumen changed my life

[@TheIncredibleStories]

Lumen completely blows my mind. Just a genuine game changer for the entire industry.

[@gabbbb5492]

genuinely and literally

[@tommosby8833]

Really good use of SDFs. 2 questions though... 1. How long does it take to re-import meshes with SDFs enabled for a big AAA project? When compared to non-SDF import. 2. The use of Lumen lighting cache is obvious due to its temporal nature. I would like to know if the FInal Gather option is also controlling the number of frames contributing to the final lighting of Lumen? Or if it is just a separate PostProcess above Lumen.

[@mogmaximus]

1. About 12 minutes 2. Yes, it is controlling the number of frames contributing to the final lighting of Lumen!

[@Karlettto89]

Great overview! I have a question, when working on a scene, and I run the stats, I noticed that with lumen active there is a considerable chunk of the render time dedicated to DiffuseIndirectAndAO. LumenScreenProbeGather and LumenReflections are the ones taking the longest to render. May I ask what are those, and where to look for optimization? Thank you!

[@spacepirate9882]

To me : - LumenScreenProbeGather : The tracing pass of Lumen. Collecting surface data and building the surface cache - DiffuseIndirectAndAO : The injection pass of computed color bleeding and AO to the base color and AO buffers - LumenReflections : The injection pass of computed lumen reflections to the reflections buffer. For optimization : - Global tracing is less expensive than detail tracing in project settings - Final gather quality in post process settings -> Lumen Global Illumination - Quality in post process settings -> Lumen reflections - Cost is heavily tied to screen resolution. Lowering screen resolution percentage with TAA gen 5 enabled (on by default in UE5)

[@Karlettto89]

@@spacepirate9882 OOoooh! That is a great answer! Thank you! Gotta get used to the new terminology :) Thank you again!

[@joelbalyeat1476]

Totally sick!

[@fireaza]

An enlightening video!

[@ChaojianZhang]

14:58 15 Years now since I started learning about 3D, and this simple room with 4 walls and a floor makes me wanna cry🤣. This is truly a moment of triumph for the development of computer graphics!

[@ChaojianZhang]

I remember how much pain it is to configure GI and Final Gathering for Maya - now I use Blender as my main modeling/rendering software.😁

[@ChaojianZhang]

By the way the Use Case room demo seemed to have enabled "Extend Default Luminance Range in Auto Exposure", also inside Post-Processing Volume we need to enable Lumen as Global Illumination method and crank up Final Gather Quality and Quality in order to obtain similar effect as shown in the video. However I am still having this wobbling effect of shadows.

[@ChaojianZhang]

Also there can be this huge shadow artifact on the side wall depending on your sun direction😢.

[@ChaojianZhang]

17:47 Use hardware acceleration. (Post-Processing Volume) Reflection - (Lumen) Reflection Quality (seems not very effective with software ray tracing, for the interior demo scene at least; Haven't tried effectiveness of distance field, but detail/global toggle not working well for interior scene). Final Gather at 4 is most effective.

[@user-dp6rf3ve4m]

计算机图形学终于能把4面墙加1个地板给收拾妥当了。

[@Turgineer]

The optimization brought by Unreal Engine 5 is great.

[@seehr]

I'm glad I saw this video.

[@mariothoughts]

Indirect lighting is great

[@rootofminusone]

thank you Epic for making this tool free

[@damysticalone87]

My KZbin Channel / Mein KZbin Kanal: kzbin.info kzbin.info kzbin.info kzbin.info kzbin.info/about KZbin search username damysticalone87 KZbin damysticalone87 My Odnoklassniki profile / Mein Odnoklassniki Profil: ok.ru/eugenzhenyak ok.ru/eugenzhenyak/statuses ok.ru/eugenzhenyak/statuses/all ok.ru/eugenzhenyak ok.ru/eugenzhenyak/statuses ok.ru/eugenzhenyak ok.ru/eugenzhenyak/statuses ok.ru/eugenzhenyak ok.ru/eugenzhenyak/statuses/all ok.ru search username eugenzhenyak Odnoklassniki eugenzhenyak www.skype.com www.skype.com/de www.skype.com//ru My free main site: ok.ru/eugenzhenyak/statuses/all

[@venger5705]

Sooo GOOD!

[@ShwanLoghmani]

really awsome ☝️☝️😎👍👍👍

[@LivingTheDream77]

we need ue5 asap, its been 1.5 years since the reveal.

[@pushthebutton4602]

Good luck!

[@patrickunderwood2630]

The future is bright!

[@irtezamasud1079]

What a piece of software!

[@DevGods]

It would be nice to register certain materials and objects for lumen. So that only chosen materials are calculated in lumen. That way we could default other materials like glass or weapon sights to what UE4 uses. Until you guys fix the translucent materials. I might be wrong but how are ppl lighting hair in lumen? Isn’t it a translucent material that uses alpha masking? Is that supported in lumen?

[@Jafoss]

Pretty sure translucency is supported by Lumen, you can even see it in action in this video demo, at the 5 minute mark you can see glass windows. You might be confusing the lack of support with Nanite. Which is another misconception. Nanite is enabled *per mesh*, it is not a global LOD system, you can use traditional LODs on assets that require translucency, like foliage and glass.

[@DevGods]

@@Jafoss I’ll have to double check I may be wrong

[@avicohen2k]

Hmm, better then most tutorials and webinars so far!

[@luminegamedev6875]

Paulo Souza is always best at presenting

[@cg.man_aka_kevin]

13:47, if you notice, the image of the tool for rotate light has green, red, and blue axis colors, it turns out that there is a global illumination effect too...

[@acspace3d602]

Twinmotin needs this, now!

[@j2only007]

What about transperancy improvements for single skeleton mesh or static mesh with multiple sub objects occluded with eachother?

[@andreytrukhachev7417]

Lumen is great! But I can’t achieve the mirror quality at the windows reflections. In some cases it helps to add additional reflection plane, and tweaking its parameters. Also when reflection plane is added it starts to lag and FPS is falling. And what is the solution for the convex glass surfaces?

[@ciixo8510]

Reflection plane is realtime and realtime reflection is always performance heavy, if your plane's normal is upward aka its looking to sky, best thing to do is to bake a reflection in to the surfaces and to the bounds of the probe and use screen space reflection, the baked reflection is to minimize the visual visiblity of SSR screen edges smoothing

[@andreytrukhachev7417]

@@ciixo8510 thank you for the answer. The bad thing is that Lumion didn’t work with baked reflections, at least as I tested. So if I will bake the reflection I would have to bake the whole scene and use the lightmaps instead of Lumion. Am I wrong?

[@ciixo8510]

@@andreytrukhachev7417 i'm actually an environment artist in unity HDRP so i don't know much about ue5, but with the logic of baked reflection being just a cube map getting projected on objects, i don't think that ue5 would have a problem with using that and lumen at the same time, and if it currently is in this way, it would probably be doable in the full release!

[@user-ik8vy1rg8f]

The new UI for UE looks a lot more modern.

[@mosamaster]

Expecting to see this in action in S.T.A.L.K.E.R 2 soon

[@OwenTuson02]

Powerful af

[@iamsaood]

Very very useful video

[@ayushkumarjha9921]

Can't wait to use UE 5.

[@mikhailgavrilov4342]

Just download EA version) Already good enough to start prototyping stuff

[@gtnardy]

vai brasiliam, otimo video Paulo!

[@isaiahnedd434]

I feel like u can incorporate lumen with rtx like some kind of real time light simulation as the gym automatically adapt n scans the area while using light n rtx would work at a faster rate giving lumen a better performance,u can ray trace through lumen

[@hawkera8586]

Does anyone know what are those artifacts around the sphere at 14:30?

[@NightVisionOfficial]

I can't wait to try making maps on this baby C: Want have a game to do maps for first, maybe on steam so I can use workshop

[@Timeyy]

Epic should make a new Unreal Tournament game with UE5, that would be amazing to make maps for.

[@CHITUS]

Emissive materials acting as lights without building lighting? What a time to be alive

[@LeoChou]

16:08 is good blueprint tutorial for sun rotate!

[@nikodemolico]

is there any way to make a material look transparent but able to block the light? for example to use it when something blocks the llight from a door or a window but animating the visible object with an offset from the transparent one to match th movement with the light calculation delay?

[@joseph.cotter]

So, building the cache from multiple points sounds a lot like light probes but in real time rather then baking... What is the difference and how is it able to happen in real time? Is it that the process of using light cards and building a cache (which works as a quick reference) is more of an approximation that is "good enough" for a quick/dirty GI solution while being faster than the method light probes use to bake out light maps?

[@Monster01D]

And God said, “Let there be light,” and there was UE5.

[@m2virtual_com]

GOD IS THE SERVER

[@TrazynTheViewer]

*Wise* AI(GPT-3) : I believe in god as a creator

[@ruijikisu]

When i tried to put Final Gather or Reflection Quality to the values in the video it doesnt work, both are clamped at 2 for me.

[@gabrielbombonato5757]

Congratulations

[@SimonBuchanNz]

With the limited testing I've done, I can't get rid of the "slime trail" when revealing indirectly lit geometry, but I don't see it in any other footage. Is there something dumb I'm doing?

[@thechronicgrump3906]

Just posted that as well, I’m having the same issue, crapload of ghosting. I’m guessing either it’s they have an insanely good GPU or they’re using a newer build of UE5 that has a lot of lumen fixes implemented

[@billymays8864]

@@thechronicgrump3906 it's likely that they are using a newer build

[@MPRX87]

You need a GPU that can run at a higher frame rate, due to how Lumen recycles previous frames. Ghosting is pretty visible if you're only getting like 30fps. At 100 fps, it's faaaaar less obnoxious.

[@LuminousLabs]

Will translucency be supported at launch for Lumen?

[@ilikecutepeople]

Lumen is a game changer for sure but it seems like the HDRI backdrop does not seems to work well with it. More specifically, the lighting seems to be blocked off. Not sure if anyone faces the same issue as me.

[@kinggore5229]

This would be cool for gamers like 5 years later.

[@archjob943]

merci bcp

[@ange501048123]

Does spotlights and point lights use lumen? Or just directional lights and sky lights?

[@andregomessoares]

All of them

[@ange501048123]

@@andregomessoares that’s a relief , cheers man

[@emotionsgaming9355]

So strong ^^

[@hanyanglee9018]

Is this something still based on ray tracing but with some adjustment to match the need of real time rendering? And if someone has some device that runs as fast as a thousand of 3080 or even faster, this could also be good enough and not deprecated at all? Like what we would probably meet in 20 or 30 years?

[@TGTID]

Lumen results differ strongly from my MacBook pro 2017 vs my windows workstation precision 5820. Anyone have any cool tricks to get macs (Intel based) to get crispier look? Settings? (I'm focusing on visuals, not games)

[@singh-wz4ql]

is there any way to increase the distance of gi beyond 200m ??

[@Native_Creation]

Is it possible to "fake" the screen space lighting so that it still keeps the bounce colors for objects before they enter the camera frame?

[@waltage]

what about precise occlusion and shading of actors?

[@danielwhitehead8965]

I have a wall that lights up when walking around the corner and then as u get near it, the lighting dims down. It’s a jarring effect. Anyone know how to correct it?

[@Ebb0Productions]

Does it work for VR?

[@AlexAlex-tl7kd]

I wanna try to use UE5 in mobile Cool video

[@harrysanders818]

They even support proxy meshes for mobile when using nanite.. so even if you build with nanite.. the project remains scalable. Try watch the recent video on nanite where it us shown. Super interesting.

[@adriangabrielgramada1016]

Felicitation to everone that was involved in this dramatic revolution that the world of graphics has not seen for ... for ever, really :) So many tries at hardware and software to get all that in real time. The most and still very highly worthy approach that is still a player is Euclideon with their unlimited resolution search algorithm. Dedicated raytracing hardware, Nvidia's all GI & raytracing RTX, Octane RENDER and so, so many others have practically become irrelevant for basically everything ... from gaming to presentations :) ABSOLUTELY WONDERFUL ... What Crysis seeded Unreal finished. Now the QUESTION WOULD BE : BUT CAN IT PLAY UNREAL 5 (or latter) ? And even more amuseingly I suspect the answer will be YES FOR MOST OF THE HARDWARE NOT JUST THE VERY BLEEDING EDGE ONE !!!

[@teammax6303]

Can't wait for translucency reflection solution...

[@vignitres]

how the hell is this even possible? I can't wait to play with it this weekend!

[@Seecondchance]

Is it possible to adjust the amount of sky shadowing from the Skylight so that interiors look brighter? Is it still possible to use an ambient light that is not affected by anything while using Lumen?

[@NextWorldVR]

Increase Secondary/bounced light im details...

[@Seecondchance]

@@NextWorldVR Do you mean the "Indirect Lighting Intensity"? I tried changing that but it doesn't seem to have any effect while using Lumen.

[@spacepirate9882]

@@Seecondchance This is for static lighting, not dynamic. If you want your interiors to look brighter while keeping physical accuracy for lighting, you're better tweaking the autoexposure.

[@Seecondchance]

@@spacepirate9882 Oh ok, I thought you would always use dynamic lights with Lumen. Is there no way to make a global ambient light like the previous Skylight anymore?