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Really! Source works now? I tried building it when the team went on hiatus and it kept failing. It is so good to hear that these fixes and improvements exist! This will be wonderful. Stochastic direct lighting is one of the headline features I’m really excited for, and I can’t wait to see if the quality will be acceptable enough to replace some of the far more limited raster methods.
Yes, it does!
How can I check that kind of lighting? (I’m not sure what it is)
Stochastic lighting is Basically epic’s version of RTXDI, so it selects which lights to shadow via ray-tracing and can (theoretically) scale up to an arbitrary # of lights at a fixed cost. As for how to enable it, I don’t know, bc I’ve never had a successful build of an engine version with the feature set.
The point of the technology is basically to have a local lighting solution that’s cheaper than VSMs but better than regular shadowmaps, and can scale up to many lights. I’d say it’s sort of nanite for direct lighting, but that comes with with so many caveats and exceptions that it’s a bad analogy.
the 5.4 preview builds, rn? i’d not mind a looksie. which commit i gotta build? do tell… 
Sounds great!
Is it maybe related with the Restir cvars I mentioned time ago? (I think you talked about this after that)
@glitchered , I built it yesterday from main branch. I usually don’t have problems when compiling from source.
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Oh, wow!
I see it’s not Restir (it still doesn’t work), but tested stochastic and it’s so promising!
I have enabled it and went from 34FPS to 47FPS in a demandant archviz scene, with minor visual difference. Shadows are something like slightly more blurry in their edges, but the worse point is that it will be more noticeable in thin objects’ shadows (like the legs of a chair), looking a little pixelated. I haven’t found a way to increse the resolution or sampling; maybe it’s still not available:
The best option (for this, specifically), for the moment, is to increase the screen percentage (100%):
Without stochastic, but ray traced:
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@glitchered @jblackwell its building fine for me as well for the last couple of months (Im usually testing new builds every weak or so)
Mak sure that you have NET 6 and all the correct Visual studio installer components checked
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i’m not a pro, but dude… i’m not an amateur either. i have everything installed i need. (not just for unreal coding)
pretty sure i’ve just been unlucky and picked the dailies that did not build.
(i’m out of space rn anyway. custom 5.3.2 build taking it. gotta stay for some shader dev for an eventual future project.)
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I do think I just got unlucky in this case, as to @glitchered’s point, not every version is guaranteed to build, especially with some of the fundumental changes they’ve been making. I’m happy to retry it, but it’s hard to get the 370-ish GB I need in order to actually build it successfully. If anyone knows any way to cut down on bloat, I would be grateful.
my 5.3.2 custom build takes “only” 230 GB. (you gotta laugh typing ‘only’ 230 xD) it’s from the “release” channel tho. is the main branch more bloated? i don’t remember how big the 5.3 daily build was, i compiled back then. i only build the UE5 project, not the whole solution. also development editor config is basicly the “release” build without additional debug bloat. you sure you used that one?
I barely touch development editors beyond what it takes to build; what’s the distinction between building the project vs. the whole solution?
the solution contains other projects/programs. this may take a while longer to compile. i think it built for over 10 hours the last time i tried that. the dependencies for the editor only project are compiled anyway, but the time should be a lil shorter. i built 5.3.2 in 2:30 something hours on my lil 6 core.
and i just hit the button and try the main branch once more. [119/5995]. 3 hours to wait? wish me luck. i hope the 5.3 DLSS code compiles without issues. gonna need a lil help pushing my hardware to the limit.
edit: so much for dlss
just 11 errors is nice tho. i think/hope i’ll figure out how to fix that. i can barely read the codebase. challenge accepted.
Checked mine and it’s 182GB total (you can delete tons of GB when already compiled and working). But I’m not an expert about compilation. The first time it was a brutal fight to make it work; I not sure if I could achieve it again after formating my PC 
Most CLs in UE5-Main should work. This is what we use for all development across the company, so breakages aren’t common and if something is broken then it’s fixed ASAP. Maybe you have a wrong Visual Studio version or are missing some dependencies. At the moment recommended version is 17.7.x. You can check it in Engine\Source\Programs\UnrealBuildTool\Platform\Windows\MicrosoftPlatformSDK.Versions.cs.
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no dlss, atm (i’m not pro enough to fix it, rn)… but we we building shaders. and use a humble amount of space. all good. 
let’s see what you done the past months.
Thank you! I’m going to look into this. I’m not going to claim to really know what I’m doing, so all of the help and education is very much appreciated. Thank you!
Where do you enable it in 5.4 (github version)? Just made a new build and can’t find it.
I did notice in this 5.4 version though, when using Lumen and VR (openXR), in one eye the reflections are glitching / flickering all the time. Crossing fingers this gets fixed before the official 5.4.0 release. Can’t report this in the bugtracker until then (or…?)
Just search for a cvar called something like stochastic enable. If you can’t, I will find it later.
PD: Reflections in one eye (I don’t remeber well, but the right one?) are broken since UE5.0 :(. Already reported months ago (and some other bugs too), but nobody cares.
AFAIK, Stochastic shadows are meant as a supplementary shadowing method for non-hero lights, so it makes sense that you’re seeing speed be prioritized over quality. I’d imagine that hero lights would be employing VSMs or the similar, because the lack of quality is quite noticable.
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