Unreal Engine Preview


A Preview of the upcoming release is now available via the Epic Games Launcher and GitHub. We have made this Preview available so that our developer-community can help us catch issues before the final release. As fixes are implemented, we will release updated previews throughout the development cycle. Please be aware that the preview releases are not fully quality tested, that they are still under heavy active development, and that they should be considered as unstable until the final release. Developers should not convert their projects for active development on preview releases. Please test on copies of your project instead.

We encourage users to check out the preview to try new features and inform us of any issues which we may not have caught. A Known Issues List is provided below which will be updated periodically. If you discover any additional issues with this preview release, please report the on the Bug Reports section of the Unreal Engine AnswerHub.

Preview Summary

This list provides a brief summary of updates in this release. Full release notes will be made available with the final release. We may not be able to provide additional information about updates at this time.

  • Editor/Tools Updates:

    • Sequencer is now a supported that combines the power of a non­linear editor with 3d animation editing to allow you to produce in-­game cinematics as well as a sequence of shots for film, tv, and previsualization. It’s also designed so that multiple artists can work on a shot together or across multiple shots.

      • Rearrange shots like a traditional non­linear editing package

      • Create alternate takes of a shot and rollback with ease

      • Make per shot tweaks and spawn shot specific actors

      • Designed for collaboration

      • Automatic track creation based on actor type

      • Standardized keyboard shortcuts

      • Auto­keyframing

      • Embedded track and key editing/creation widgets

      • User­definable track coloring

      • Keyframe shapes and colors defined by interpolation behavior

      • Folders and labels for organization

    • Cinematic Camera Actors coupled with new Camera Rig Actors provide filmmakers as well as novices with the ability to create realistic camera shots with ease.

      • Customizable lenses and filmback settings

      • Focal length

      • Look at tracking

    • Cinematic Viewport is new, streamlined and allows you to view a sequence of shots for dailies in filmmaking.

      • Embedded timeline and transport controls

      • Frame numbers indicating shot in and out cut points

      • Overlays and framing helpers for composition

    • Sequence Recording allows you to record gameplay and immediately place the recorded elements into your shot. You can even make a recording while playing back a previous recording.

      • Record gameplay into skeletal animation, transform, event, and audio tracks

      • Automatic track generation for re­editing the recording

    • Audio Localization (Preview) - improves our built-­in support for audio localization (via dialogue wave and dialogue voice assets) to the point where you’re now encouraged to try and it out and provide feedback.

      • Spoken text is now gathered from dialogue wave assets and included in your PO files for translation along with your other asset based text.

      • Several new commandlets have been added to facilitate the recording and importing of audio for your dialogue wave assets (these are also integrated into the Localization Dashboard).

        • ExportDialogueScript ­- Exports a per­culture CSV file containing each line of dialogue and its associated filename.

        • ImportDialogueScript -­ Imports a copy­edited per­culture CSV file and updates any translations with the recorded dialogue.

        • ImportLocalizedDialogue -­ Imports per­culture recorded WAV files and generates localized dialogue and sound wave assets.

    • Unreal Editor in VR (Preview)

  • Platform Updates:

    • Xbox One

      • Async compute is now supported. This allows the GPU to use spare resources during drawing to do other work, resulting in faster overall frame times on GPU. This is currently used by the reflection environment and SSAO passes with more coming in future.

      • DX11.x Fast Semantics is now turned on by default which saves CPU time. DX11.x Legacy is now deprecated. We anticipate moving to DX12.x by default in a future release and removing DX11.x entirely.

    • PS4

      • Support for SDK 3.508.031

  • VR Updates:

    • Improved Stereo Layers Support - Layer support now works on all platforms, and has been improved to be more user friendly

    • VR Loading Movies - You can now have framerate-­independent loading movie support.

    • OSVR Support UE4 will now ship with OSVR support out of the box. For more information, visit http://www.osvr.org/

  • Framework Updates:

    • Added ability to use lower LODs for StaticMesh collison

    • Default collision from static mesh asset

    • Animation Node: Twist Corrective can apply a MorphTarget curve value when a twist is overdone

    • Dynamic SoundClass adjustment overrides in sound mixes

    • AnimComposite can be used in AnimMontage or AnimComposite. With this change, now AnimSequenceBase (previously only AnimSequence) is supported through montages or composite. If you’d like to create your own AnimSequenceBase, it should be easier to support with this.

  • Rendering Updates:

    • High Quality Reflections

      • High Precision Static Mesh Vertex Normal/Tangent Encoding

      • Custom Resolutions for Sky Cubemaps and Reflection Probes

      • Custom Cubemaps for Reflection Probes

      • High Precision GBuffer Normal Encoding

  • Blueprints Updates:

    • Cooking Blueprints into C++ (Experimental Beta) allows you to package Blueprints into native source code.

      • Enabled in editor, through your project’s Packaging Settings: Experimental => Nativize Blueprint Assets. Can also be invoked by passing -NativizeAssets as a to the UAT BuildCookRun script

      • Generated source is saved as a plugin in your project’s intermediate folder, under: …\Intermediate<PLATFORM>\NativizedAssets\

      • Can exclude certain Blueprints from the process in your game’s DefaultEditor.ini file (under [BlueprintNativizationSettings]). General “types” of Blueprints can be excluded: +ExcludedBlueprintTypes=/Script/UMGEditor.WidgetBlueprint. Specific assets can also be excluded: +ExcludedAssets=/Game/Blueprints/MyBlueprint

    • Mask Field Variables - Integer properties can now be declared as being a bitmask, and optionally associated with an enum which encapsulates bitflag values.

  • Mobile Updates:

    • Vulkan Mobile Renderer (Experimental) as shown in the ProtoStar demo shown at the Samsung Galaxy S7 Unpacked event in Barcelona

    • High Quality Mobile Post Processing

      • Improved Depth of Field quality

      • Filmic Tonemapper

    • More Shadowing Options for Mobile

      • CSM shadows for dynamic objects blended with precomputed Lightmass shadows

      • Planar reflections

    • GPU Particles on High-end Android and iOS devices

      • Apple devices with A8+

      • Android 6.0 with Adreno 4xx and Mali-T7xx (Galaxy Note 4, Note 5, S6, S7, Nexus 6P and others)

    • Web Browser UMG Widget on iOS

  • Mobile Landscape & Foliage Updates:

    • Grass and Foliage Scalability

      • Ability to reduce grass and foliage density based on quality levels

    • New Scaling and Alignment Options for Landscape Grass

    • Landscape Collision Improvements

      • Simplified Player Collision for Landscape

      • Collision support for spline meshes created at runtime (GitHub contribution)

Known Issues List

This is a list of unresolved high priority bugs in our Preview engine release. We will attempt to resolve critical bugs before the final release, other bugs that do not block development or have workarounds may be marked to be fixed in one of the future hotfixes or major releases.

Please be aware that this is not a comprehensive list of all engine bugs, it is simply a snapshot of some of the latest bugs discovered with this preview that we aim to fix prior to release. This list will be periodically updated with new additions and to reflect which ones have been fixed, so be sure to check back!

Important Known

  • Google VR (Daydream) doesn’t work in the Launcher release, but is functional via Github (UE-31186)

Known Issues in Preview 5 - CL 2986880

UE-31090 AI Perception Not Showing Up in Debugger
UE-31099 Renaming an input mapping does not generate a warning when compile a blueprint using that input
UE-30625 Crash On dedicated server when adding a variable set to RepNotify Character blueprint and playing in Editor
UE-31036 Sound volume does not change when moving past the Non Focus Azimuth range if set to greater than 90 degrees
UE-31028 Stop Quietest Concurrency does not remove the quietest sound
UE-31210 Empty PATH env var when compiling with 2015
UE-31109 Right-clicking the .uproject file and selecitng “Generate Xcode project” does nothing
UE-30823 ShooterGame packaged for Win XP generates a dll error when trying to run the executable
UE-30813 Deployment Server has stopped working dialog box when launching onto tvOS from Windows
UE-30301 Multiple Content Examples levels need lighting rebuilt
UE-30755 Subway Sequencer rendered sequence frames not matching frames in sequencer
UE-31186 GoogleVR Binaries missing in Binary Build of Editor

REMEMBER: Please report any new bugs you find to the UE4 Answerhub

Sweet! Are there any docs about these (for Gear VR preferably)?



Could somebody elaborate on what the “High Quality Reflections” rendering update really means? The cube maps are no longer limited to 128 x128?

Just got an update on the launcher thought it was new version for 4.11 (some bugs that still hasn’t been resolved) anyway this is cool too, specially the sequencer to try out! Sweeet Epic!

We don’t have further information about these topics at this time.

One part of this: "We moved to encoding our normals as a two component, 16 bits per channel, vector using Octahedral Mapping. Tangents are encoded into four channels: 10 bits per channel for the basis vector components and 2 bits to store the tangent basis determinant sign. This encoding gave us a good balance between decompression ALU and quality."

Nice :slight_smile: I really want to get my hands on the sequencer.

YES! So so excited for this release! Gonna have some fun with sequencer today :slight_smile: Thanks to all at Epic for these speedy and awesome updates!

OMG! So fast after 4.11! :smiley: I’m shocked :open_mouth: Thank you Epic <3

So, is there a REASON for cooking BPs to C++, other than just wanting to look at C++ code? Does this bypass the aforementioned interop layer latency, or is the performance impact expected to be negligible when cooking down?

I suppose the short version is: is there a reason to cook BPs to C++ before cooking game assets when packaging?

BPs are a bit slower at runtime than C++, so it might be worth cooking them to C++ if they are complicated or you make extensive use of them.

I dodgied up a bitmask in blueprint about a month back, it wasn’t very pretty. Thank you for giving me a better way.

When you can fix terrain tesselation problem of white cracky edges please unreal!

Have to try that Vulkan API right now.

Tested Out the some new translucent shaders and I can defiantly see the difference!

Will that only work on Xbox One and not on PC? Why?

Question about High Precision GBuffer Normal Encoding: looking at shader code in DeferredShadingCommon.usf it seems that this is actually disabled (notice commented out lines)?

float3 EncodeNormal( float3 N )
	return N * 0.5 + 0.5;
	//return Pack1212To888( UnitVectorToOctahedron( N ) * 0.5 + 0.5 );

float3 DecodeNormal( float3 N )
	return N * 2 - 1;
	//return OctahedronToUnitVector( Pack888To1212( N ) * 2 - 1 );

All of these cool things! And no proper full screen video playback independent from the gameplay. -_- Its so broke and flawed and I’ve waited 6 versions for any sort of update.

I really like that! Another great reason to use InstaLOD during your game production!!

Any that Instanced Stereo Rendering for Gear VR is planned in as well?