Unreal Engine 5.1 build

I’ve seen numerous things online regarding the experimental build of UE 5.1. Not seeing access to it as a preview build in the launcher so is it only available to select people at this point or something that has to be downloaded and custom compiled to use?

It is available on github, but will have to be compiled by the user. There is a github link on the library page in the launcher.


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github unreal main branch type main in the branches search bar. when compiled its 5.1.0. will not be compatable with 5.1.0 release branch project will have errors so just experiment with this

Has Unreal given any timeframe on UE 5.1 release?

I upgraded a project, but exceeded my Nvidia RTXGI capability, which is unfortunate.

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i have no clue. i have been currently obsessed with the unreal caustcis branch which is stuck in 4.27 but i hope it goes unreal 5 soon. its also not supporting vr well so i am thinking of making 2 games now. caustics game and a vr game with strata. so far i believe strata is working in vr just fine i have some examples of strata running on my youtube dreken productions and me playing with caustics on my newest video. once caustics is finally updated to unreal 5.1 graphics will be absolutely insane. honestly lumen is not nearly as good as ray tracing and with dlss on the frame rate is very nice. nanite is cool and i hope we can combine them soon but for now using lod’s and unreal 4.27 we can still make an amazing game i think. gonna try something really small for this 4.27 branch but as far as my testing on the 5.1 branch it is slowly becoming more unstable for plugins so you will likely not be able to build all the plugins you own for unreal 5 unfortunately getting a developer to work on an experimental branch is quite difficult as the goal has to align with theirs in their pursuit of supporting the experimental build but most developers will wait until release to touch any code as unreal may fix the bugs they created by release. after building the unreal-main branch you have to enable strata in the project settings. you can search strata. using strata is not easy yet. most materials will break but as far as i could tell with each update materials were fixing themselves so they have a system for conversion in the works i think. things look diferent in strata though much more accurate. strata + rtx caustics will be the most amazing realtime rendering we have seen yet.

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honestly lumen is not nearly as good as ray tracing and with dlss on

I have to disagree with you regarding the GI. I’m not really sure why people keep saying this even though there is plenty of evidence to suggest that lumen is a much more improved GI solution.

Even VSM’s at their current stage can do a whole lot more than the hardware raytracing shadows did, SMRT and also Nanite support to be more specific.

Have you seen this example before?

Look at how the lighting in Lumen compares to the two other solutions and decide for yourself. Even the RTXGI (I think they misspell it as RTX DI) looks way more natural than what is being produced by HW RT or the plugin.

Now to be fair I have seen some videos where people adjusted the probes in a way that makes things appear much closer to Lumen, such as in the case with this video that William did:

But the tradeoff is a massive drop in performance as well as the time it takes to set all of this up. And even then this feature still appears to be lacking in some areas, that gap between the two methods widening even further when hardware is used to boost lumens capabilities.

Add to this the improvements coming to Lumen in 5.1 like scalability, I’m not sure the RTXGI solution is gonna continue to be a viable alternative at that point.

i think that maybe my perspective might be altered. im on the nvidia rtx caustics branch and they have additional ray tracing features. lumen is fantastic at gi and i will admit it probably beats ray tracing classic but on the down side lumens reflections are very poor. with dlss on i can turn ray bounces up to 50/50/50 for all and i do lag but for 150 rays on im at 45 fps with dlss on using a mirror bounce setup. i do use william’s videos a lot so thats where my opinion is also altered. i like to tweak everything to my liking and i think if i remember lumen just dosent have all the same options as ray tracing yet as far as i can tell. im doing a video later tonight on enabling caustics rtx. for now this is my only reason for staying in unreal 4.27 is that rtx caustics is stuck there. i want rtx on unreal 5.0 because lumen gi will save me a lot and ray traced reflections can kick in after. lumen also had a lot of problems like edge screen blurring and update lag. i think increasing the update speed just made me either lag or poor image quality. i think they are actively workoing towards a ue5 caustics branch and once we can combine these all we will have the ultimate visual experience. unreal 5.1 with rtx caustics is what im really excited for once we get strata support for caustics its going to be nuts. i dont expect strata and rtx caustics to play nice together but if they just work together no issues its going to be amazing

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lol i was just about to watch this video because i havent been using rtx gi yet it does not use ray traced reflections i guess. one thing about lumens reflections it did have was pretty acurate lighting comparisons. ill see how rtxgi works in this caustics branch maybe theres special tweaks for rtx gi like they tweaked ray tracing system.

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