Unreal Engine 5.5 Preview

Amanda.Schade · October 1, 2024, 7:32pm

Download Unreal Engine 5.5 Preview from the Epic Games launcher, GitHub, or for Linux!

Unreal Engine 5.5 is another milestone on our journey to help you push the boundaries of high-fidelity 3D experiences and AAA-caliber content—and Preview 1 is now available!

MegaLights enables you to use orders of magnitude more lights than ever before—all movable, dynamic, with realistic area shadows and the ability to light volumetric fog. As seen in the live demo at Unreal Fest Seattle, our intrepid hero Echo navigated a scene illuminated by over 1,000 shadow-casting lights in real time running on PlayStation 5.

UE 5.5 also brings exciting rendering improvements: Nanite can now render Skeletal Meshes incredibly fast (currently an Experimental feature) and Path Tracer is Production-Ready.

Animation authoring tools are more robust and easier to use in 5.5, with a Production-Ready Skeletal Editor, enhanced Deformers, and the addition of much-requested features like TimeWarp curves and Animation Layers. Virtual production tools have made big steps forward with Production-Ready SMPTE 2110 integration for in-camera VFX (ICVFX), multi-camera support, and inner frustum splitting.

To support high-end games on mobile, UE 5.5 brings new features that include Mobile Preview functionality, enabling you to match device visuals and ensure players are getting the best possible experience for their device’s capabilities.

What else is coming? Check out more of the featuring coming in Unreal Engine 5.5 on the Roadmap.

Unreal Engine 5.5 Roadmap

Keep in mind, preview releases are not fully quality tested, are still under heavy active development, and should be considered as unstable until the final release. We recommend that developers make a copy of their projects for testing these builds, not to convert their projects.

Known & Fixed Issues

Unresolved issues in 5.5 Preview targeted to be fixed by the 5.5 Release
Unresolved issues in 5.5 Preview
Issues fixed in 5.5 (the fix may not be included in the current available Preview)

If you discover any additional issues with this preview release, please report them using the guidelines in the link: How to Report a Bug

UElaci · October 1, 2024, 7:47pm

Still no hwrt support on mac m3? Why?

FPChrisFP · October 1, 2024, 8:08pm

Don’t see it in the Launcher?

Miguel1900 · October 1, 2024, 8:15pm

Hi @Amanda.Schade !

All the afternoon compiling my plugins for 5.5 and they work fine. But when trying to migrate a project (it works aparently fine in Editor), it will give a Fatal Error when packaged. This is a small, almost ready to ship, game. (I know Prev is not intended for production, that’s why I have confidence in the future release to be fixed).

That one error didn’t generate any logs as it was packaged as Shipping with Project Launcher:
Captura de pantalla 2024-10-01 22.19.37

But when packaging in Development:

Log file open, 10/01/24 21:57:05
LogWindows: Failed to load 'aqProf.dll' (GetLastError=126)
LogWindows: File 'aqProf.dll' does not exist
LogProfilingDebugging: Loading WinPixEventRuntime.dll for PIX profiling (from ../../../Engine/Binaries/ThirdParty/Windows/WinPixEventRuntime/x64).
LogWindows: Failed to load 'VtuneApi.dll' (GetLastError=126)
LogWindows: File 'VtuneApi.dll' does not exist
LogWindows: Failed to load 'VtuneApi32e.dll' (GetLastError=126)
LogWindows: File 'VtuneApi32e.dll' does not exist
LogWindows: Custom abort handler registered for crash reporting.
LogCore: Display: UTS: The Unreal Trace Server binary is not available ('../../../Engine/Binaries/Win64/UnrealTraceServer.exe')
LogTrace: Initializing trace...
LogTrace: Finished trace initialization.
LogCsvProfiler: Display: Metadata set : platform="Windows"
LogCsvProfiler: Display: Metadata set : config="Development"
LogCsvProfiler: Display: Metadata set : buildversion="++UE5+Release-5.5-CL-36679577"
LogCsvProfiler: Display: Metadata set : engineversion="5.5.0-36679577+++UE5+Release-5.5"
LogCsvProfiler: Display: Metadata set : os="Windows 11 (23H2) [10.0.22631.4169] "
LogCsvProfiler: Display: Metadata set : cpu="AuthenticAMD|AMD Ryzen 9 3950X 16-Core Processor"
LogCsvProfiler: Display: Metadata set : pgoenabled="0"
LogCsvProfiler: Display: Metadata set : pgoprofilingenabled="0"
LogCsvProfiler: Display: Metadata set : ltoenabled="0"
LogCsvProfiler: Display: Metadata set : asan="0"
LogCsvProfiler: Display: Metadata set : commandline="" GameTech""
LogCsvProfiler: Display: Metadata set : loginid="098d78e649e9455ab6c046a04361272d"
LogCsvProfiler: Display: Metadata set : llm="0"
LogPakFile: Initializing PakPlatformFile
LogIoDispatcher: Display: Reading toc: ../../../GameTech/Content/Paks/global.utoc
LogIoDispatcher: Display: Toc loaded : ../../../GameTech/Content/Paks/global.utoc, Id=ffffffffffffffff, Order=0, EntryCount=1, SignatureHash=8A1464FB4AF8634E192E16612A82A29B8B4805CE
LogIoDispatcher: Display: Mounting container '../../../GameTech/Content/Paks/global.utoc' in location slot 0
LogPakFile: Display: Initialized I/O dispatcher file backend. Mounted the global container: ../../../GameTech/Content/Paks/global.utoc
LogPakFile: Display: Found Pak file ../../../GameTech/Content/Paks/GameTech-Windows.pak attempting to mount.
LogPakFile: Display: Mounting pak file ../../../GameTech/Content/Paks/GameTech-Windows.pak.
LogIoDispatcher: Display: Reading toc: ../../../GameTech/Content/Paks/GameTech-Windows.utoc
LogIoDispatcher: Display: Toc loaded : ../../../GameTech/Content/Paks/GameTech-Windows.utoc, Id=66d80b935d9758bc, Order=4, EntryCount=3759, SignatureHash=8A8F5FC1812E1E266061C3EDF41BA04940550AF3
LogIoDispatcher: Display: Mounting container '../../../GameTech/Content/Paks/GameTech-Windows.utoc' in location slot 0
LogPakFile: Display: Mounted IoStore container "../../../GameTech/Content/Paks/GameTech-Windows.utoc"
LogFilePackageStore: Mounting container: Id=66d80b935d9758bc, Order=4, NumPackages=1953
LogPakFile: Display: Mounted Pak file '../../../GameTech/Content/Paks/GameTech-Windows.pak', mount point: '../../../'
LogStats: Stats thread started at 0.163062
LogAssetRegistry: Premade AssetRegistry loaded from '../../../GameTech/AssetRegistry.bin'
LogIris: FNetObjectFactoryRegistry::UnregisterFactory is unregistering factory: None name: NetActorFactory id: 0
LogIris: FNetObjectFactoryRegistry::UnregisterFactory is unregistering factory: None name: NetSubObjectFactory id: 1
LogICUInternationalization: OS requested locale 'es-ES' is not supported. Using the OS requested language of 'es-ES' as the locale.
LogICUInternationalization: ICU TimeZone Detection - Raw Offset: +1:00, Platform Override: ''
LogInit: Session CrashGUID >====================================================
         Session CrashGUID >   UECC-Windows-399DAF6040F68F2BBF3D4FBA9253E416
         Session CrashGUID >====================================================
LogInit: Display: Loading binary GConfig...
LogConfig: No local boot hotfix file found at: [../../../GameTech/Saved/PersistentDownloadDir/HotfixForNextBoot.txt]
LogAudio: Display: Pre-Initializing Audio Device Manager...
LogAudio: Warning: Audio:AllWaveFormats is not defined, defaulting to built in formats. (BINKA, ADPCM, PCM, OPUS, RADA)
LogAudio: Warning: Audio:FallbackFormat is not defined, defaulting to 'ADPCM'.
LogAudio: Warning: Audio:PlatformFormat is not defined, defaulting to 'ADPCM'.
LogAudio: Warning: Audio:PlatformStreamingFormat is not defined, defaulting to 'ADPCM'.
LogWindows: Error: appError called: Assertion failed: NumFailedFormats == 0 [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\AudioDeviceManager.cpp] [Line: 378] 
Failed to find these required AudioFormats: [ 'BINKA' 'ADPCM' 'PCM' 'OPUS' 'RADA' ]

LogWindows: Windows GetLastError: La operación se completó correctamente. (0)
LogWindows: Could not start crash report client using ../../../Engine/Binaries/Win64/CrashReportClient-Win64-Debug.exe
LogMemory: Platform Memory Stats for Windows
LogMemory: Process Physical Memory: 636.98 MB used, 875.76 MB peak
LogMemory: Process Virtual Memory: 592.47 MB used, 832.67 MB peak
LogMemory: Physical Memory: 9345.88 MB used,  56097.90 MB free, 65443.78 MB total
LogMemory: Virtual Memory: 12375.00 MB used,  53084.79 MB free, 65459.78 MB total
Message dialog closed, result: Ok, title: The UE-GameTech Game has crashed and will close, text: Assertion failed: NumFailedFormats == 0 [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\AudioDeviceManager.cpp] [Line: 378] 
Failed to find these required AudioFormats: [ 'BINKA' 'ADPCM' 'PCM' 'OPUS' 'RADA' ]



LogWindows: Error: === Critical error: ===
LogWindows: Error: 
LogWindows: Error: Assertion failed: NumFailedFormats == 0 [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\AudioDeviceManager.cpp] [Line: 378] 
LogWindows: Error: Failed to find these required AudioFormats: [ 'BINKA' 'ADPCM' 'PCM' 'OPUS' 'RADA' ]
LogWindows: Error: 
LogWindows: Error: 
LogWindows: Error: [Callstack] 0x00007ff742f11364 GameTech.exe!FAudioDeviceManager::RegisterAudioInfoFactories() []
LogWindows: Error: [Callstack] 0x00007ff742f0dd1c GameTech.exe!FAudioDeviceManager::PreInitializeManager() []
LogWindows: Error: [Callstack] 0x00007ff742f0dc07 GameTech.exe!FAudioDeviceManager::PreInitialize() []
LogWindows: Error: [Callstack] 0x00007ff73cfddd43 GameTech.exe!TBaseFunctorDelegateInstance<void __cdecl(void),FDefaultDelegateUserPolicy,TFunction<void __cdecl(void)> >::ExecuteIfSafe() []
LogWindows: Error: [Callstack] 0x00007ff73cd51628 GameTech.exe!TMulticastDelegate<void __cdecl(void),FDefaultDelegateUserPolicy>::Broadcast() []
LogWindows: Error: [Callstack] 0x00007ff73cffdfb6 GameTech.exe!FDelayedAutoRegisterHelper::RunAndClearDelayedAutoRegisterDelegates() []
LogWindows: Error: [Callstack] 0x00007ff7446c362c GameTech.exe!FEngineLoop::AppInit() []
LogWindows: Error: [Callstack] 0x00007ff7446d2f72 GameTech.exe!FEngineLoop::PreInitPreStartupScreen() []
LogWindows: Error: [Callstack] 0x00007ff7446c8ca2 GameTech.exe!GuardedMain() []
LogWindows: Error: [Callstack] 0x00007ff7446c8f4a GameTech.exe!GuardedMainWrapper() []
LogWindows: Error: [Callstack] 0x00007ff7446cbbc2 GameTech.exe!LaunchWindowsStartup() []
LogWindows: Error: [Callstack] 0x00007ff7446d8904 GameTech.exe!WinMain() []
LogWindows: Error: [Callstack] 0x00007ff74a14ea1a GameTech.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
LogWindows: Error: [Callstack] 0x00007ffb90b7257d KERNEL32.DLL!UnknownFunction []
LogWindows: Error: 
LogWindows: FPlatformMisc::RequestExit(1, LaunchWindowsStartup.ExceptionHandler)
LogWindows: FPlatformMisc::RequestExitWithStatus(1, 3, LaunchWindowsStartup.ExceptionHandler)
LogCore: Engine exit requested (reason: Win RequestExit)

But it packages “fine” when not using the Project Launcher! However, another thing I noticed: the SetRes cvar is not working fine when packaged and it was perfectly working in 5.3.

Whops, and another error:
Captura de pantalla 2024-10-01 22.28.14

About a very different project for ArchViz, based on this pack (https://www.unrealengine.com/marketplace/en-US/product/dviz-realistic-house-archviz-project/), I got some crashes in Editor this time (GPU crashed or disconnected) when opening (I think it’s a kind of incompatibility with older ray tracing features previously enabled). In addition, I had some other kind of errors too:

First one, when opening one of the maps (but very rareyle times, it opens it!):
imagen


GPU Crash dump Triggered

UnrealEditor_D3D12RHI
UnrealEditor_D3D12RHI
UnrealEditor_D3D12RHI
UnrealEditor_D3D12RHI
UnrealEditor_D3D12RHI
UnrealEditor_Core
UnrealEditor_Core
kernel32
ntdll

And the second one:

Assertion failed: TotalResourceCount == 0 || Shader->ShaderBindingLayoutHash == ShaderBindingLayoutHash [File:D:\build\++UE5\Sync\Engine\Source\Runtime\D3D12RHI\Private\D3D12RayTracing.cpp] [Line: 1975] 
Raytracing shader with with entry point LumenShortRangeAOHardwareRayTracing doesn't match the RTPSO ShaderBindingLayout


0x00007ffa94b31de3 UnrealEditor-D3D12RHI.dll!UnknownFunction []
0x00007ffa94b2773a UnrealEditor-D3D12RHI.dll!UnknownFunction []
0x00007ffa94b633c6 UnrealEditor-D3D12RHI.dll!UnknownFunction []
0x00007ffaca8ca1ab UnrealEditor-RHI.dll!UnknownFunction []
0x00007ffaca8cf015 UnrealEditor-RHI.dll!UnknownFunction []
0x00007ffaca90f3f0 UnrealEditor-RHI.dll!UnknownFunction []
0x00007ffaca8c0514 UnrealEditor-RHI.dll!UnknownFunction []
0x00007ffab908eab5 UnrealEditor-Core.dll!UnknownFunction []
0x00007ffab908e7ef UnrealEditor-Core.dll!UnknownFunction []
0x00007ffab90b5dad UnrealEditor-Core.dll!UnknownFunction []
0x00007ffab907ad56 UnrealEditor-Core.dll!UnknownFunction []
0x00007ffab9285c83 UnrealEditor-Core.dll!UnknownFunction []
0x00007ffab96d610d UnrealEditor-Core.dll!UnknownFunction []
0x00007ffab96cd62f UnrealEditor-Core.dll!UnknownFunction []
0x00007ffb90b7257d KERNEL32.DLL!UnknownFunction []

Crash in runnable thread Foreground Worker #1

Just a direct question to live more mentally calm, please: maybe this prev. version was released faster than normal, just to arrive to the deadline of the Unreal Fest?

Thank you very much!

hzFishy · October 1, 2024, 10:05pm

There is so much features that Unity doesnt have that UE do. So why being angry here ?

Also please do not spread misinformation about what UE has

no physics determinism: chaos is fully deterministic
no fixed timestep: that’s what chaos async ticking is and there is an easy to use callback even AActor::AsyncPhysicsTickActor
No robust 2d...: true, but its easy enough to use UE with only 2D, just ignore and disable 3D stuff
No advanced enhanced input: I guess the literal “enhanced input” system doesn’t count
No powerful camera system: lets ignore UE’s whole system for cinematics
No way to disable actors: this is a Unity concept, in UE there are plenty of ways to do a “disable” behavior

Riev02 · October 1, 2024, 11:27pm

Is something bricked with editor’s performance.

I get fps drops from 120 to 15 - 45, even worse when i had editor at 240 fps.

Hold right mouse, rotate camera for 0.5s, move mouse again on screen = large fps drop related to HitproxyReadback.

There was similar high function usage related to HitproxyReadback in 5.4 but its even worse now.

Edit: Some new things i noticed

In game/compiled performance is improved
but editor itself suffers from above mentioned thing. Going from 4 ms (240 fps) or 8 ms (120 fps) to 16 - 32 ms (15 fps or so) due to HitproxyReadback in editor

Some · October 2, 2024, 12:02am

Nanite Skeletal Mesh - what’s the catch?

Exetos · October 2, 2024, 2:28am

It looks like you are new to unreal engine. Nearly everything you mentioned is already implemented except 2D but unreal engine is a 3D engine.

VinnyBlood · October 2, 2024, 2:59am

Idk if you are trolling or not. No robust 2D Engine? Eh? I’ve been working with Paper2D in Unreal for years - works perfectly, what are you ralking about? I was complaining about in regard of 2D was Orthographic Camera - the only thing where Unity was better, but since 5.3 it’s fixed! UE as of 5.3 has full support of Ortho Camera. “Enhanced Input” - that’s literally what Input system is called in UE5. Fixed Timesteps - ehhh… you know that it’s all inside a single virtual Tick() function that takes DeltaSeconds as an argument? Who stops you from handling Tick yourself and passing fixed DeltaSeconds there? AI integration was added in the previous release, altought I don’t think it’s a good idea, but ok. No powerful Camera system? Are you sure you ever used Unreal?
Let’s talk about Unity’s ACTORS. What about having a normal sane OOP structure in Unity - like EVERY OTHER ENGINE ON THE PLANET? Not being able to create subclass of Unity’s SceneObject (analogue of Unreal’s actor) is ridiculous. Instead of simple make a subclass of SceneObject, you have to use “Prefab” system which is broken and even if it wasn’t it’s still not you want as a programmer. SceneObject being able to have only one component of each class? Why? Why I can’t have heirarchy of dozens of components WITH TRANSFORMS, and treat as c# subclass of SceneObject? Leaving aside that you can’t go deep in the Unity engine, because you’re limited to c#, while Unity itself is written in c++. While in Unreal I can go into the very guts because it’s all c++.

secretnetguy · October 2, 2024, 3:09am

Was curious to check out Epic’s implementation of Nvidia’s RTXDI, but it seems to not work right now in 5.5. Enabled it on top of everything else that previously worked (atrocious performance without DLSS rn), but still getting X all over the place.

Derjyn · October 2, 2024, 5:00am

How silly. I love superfans that can only drink one flavor of Kool-Aid. The sheer tenacity of limiting one’s scope to one solution is always motivational!

Sadly, I’m still stuck here with 9 different engines (not counting an in-house basic toy engine) across 3 platforms that I have to choose between when a given project’s needs become clear. I wish I could could only choose one, and poo-poo on it when it doesn’t meet my grandiose expectations! Life would be so much simpler, my stress levels would rise, and my jolly mood would evolve into one of spite and malice for anything that appears positive and sweet.

You keep being inspirational, you rascal. Even if your bulleted list was way off the mark, accuracy doesn’t matter nowadays, anyhow, ha. Silly fact liking people just don’t get it, do they?

Now I’m off to go make a cheez-whiz themed 'schmup in Game Maker 2, with Unity running in the background for another project, while Unreal Engine 5.5 preview installs. Heck, I’ll probably start some greybox geo in Blender (perhaps, a donut? That seems groundbreaking) that I’ll export to Maya because I can, then paint it in Substance, then tweak it in Photoshop, but change my mind and tweak it Gimp instead.

In all seriousness, I’m sure the community is gonna bark hard at ya. Though you should have known that would be the result. Keep it light-hearted, and try to keep an open mind. I love Unreal Engine and Unity and all the other beautiful tools out there. If you’re forward thinking, it might be a good idea to get used to both environments, because a big fish definitely isn’t going to gobble up the other. Totally not gonna happen…

Sebastian · October 2, 2024, 5:19am

What about if your scene uses only one light - the sun. Are there rendering improvements for that scenario ? Quality or performance improvements ?

BeeGeeDee · October 2, 2024, 6:57am

I’m pretty sure the camera functionality in cinemachine has been available in UE since 4.22ish and possibly before. There’s certainly courses out there that teach this in 4 and I’ve also used cinemachine and timeline heavily in Unity too. I’m assuming you are talking tracked cameras, tracking of targets, blending between cameras for cut shots, all these good things. In fact, there’s a course by Chris Murphy which covers the camera functionality on Udemy in the first section.

AI - no thank you.

Paper2D and PaperZD combined offers pretty much the same functionality as Unity

This was in beta in 4 and released in 5.1

Set Active | Unreal Engine 5.5 Documentation | Epic Developer Community (epicgames.com)

Never used DOTS Physics so can’t comment, rarely used FixedUpdate in Unity (only when implementing physics because what I needed wasn’t there) and complex collisions are supported - I know because you can build the collision meshes inside the editor if you want.

Acolori_Medien · October 2, 2024, 8:48am

Lots of great new additions here.
Is there a reason why the skeletal mesh support isn´t listed in the roadmap though?

hwpixo · October 2, 2024, 8:50am

mGPU is totally killed? I tried to launch an nDisplay with the mGPU configuration and anything with GPU 1 assigned to it just simply does not render.

Ulrich.Thummler · October 2, 2024, 9:40am

I can’t find the preview release notes. Coming first with the final release?
Trying Megalights is awesome 200 moveable lights approx. 400% performance improvement. But shadow artefakts are hard.
Enable nanite on skeletal mesh is crashing.
Editor performance is low

VisualChris · October 2, 2024, 10:30am

I’m sorry, but training AI on FAB assets will completely destroy the market economy in the long term and will likely be insanely damaging to their reputation.
Would not do that haha

cganim8r · October 2, 2024, 11:18am

I’ve just tried to get my BM Decklink to work with 5.5 and I’m still having the same issue since 5.3, forcing me to stick with 5.2.
When using a Decklink as a BM media input, it works fine. Unreal sees the video from the SDI. I can display the video in the Media Player, created when I made a Media Bundle. However, the Media Texture creates a black, 2x2 pixel texture. Dragging a Media Bundle into the scene just creates a black plane with no video feed. Creating a Composure layer made up of several CG layers and a media layer, the media layer is black.
What has happened Epic? This worked without fault in 5.2, but it seems you have broken it for any subsequent releases - 5.3, 5.4 and, now 5.5. The Decklink 8K Pro is on your list of working hardware, but it isn’t working as it did and, from reading other threads, it’s not just the Decklink 8K Pro. Other BM cards are having the same issue. Please, sort it out.
Thanks.

UElaci · October 2, 2024, 12:31pm

Does nanite work for anyone on a mac? It doesn’t seem to be working in 5.5 but I am not sure if project got broken or nanite doesn’t work.

Oh and disabling every target RHI selection in project settings will make it impossible to load the project with this error:

Assertion failed: RequestedFeatureLevel != ERHIFeatureLevel::Num [File:./Runtime/RHI/Private/Apple/AppleDynamicRHI.cpp] [Line: 110]