Unreal Engine 4.8 Preview


A Preview of upcoming 4.8 release is now available via Epic Games Launcher and GitHub. We have made this Preview available so that our developer-community can help us catch issues before final release. As fixes are implemented, we will release updated previews throughout development cycle. Please be aware that preview releases are not fully quality tested, that they are still under heavy active development, and that they should be considered as unstable until 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 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 issue here or on Bug Reports section of Unreal Engine .

View our Twitch stream on for additional information about 4.8 release.

Also see follow up 4.8 Twitch Stream here.

4.8 Preview Summary

This list provides a brief summary of updates in this release. Full release notes will be made available with final 4.8 release. We may not be able to provide additional information about updates at this time.

  • SteamVR: HTC support!
  • Support for new Morpheus hardware and SDK, including 120Hz reprojection
  • Major rendering optimizations for landscape and foliage in huge worlds (e.g. hierarchical foliage culling and rendering)
  • Grass Rendering System for landscapes. Optimized for drawing huge amounts of grass and ground clutter with temporal LOD cross-fading.
  • Procedural Foliage System (Experimental Preview), for automatic object placement in huge environments
  • Depth of Field effects have been improved to be more physically-based.
  • Motion Blur has been improved to be more realistic
  • Morph Target Animations can now generate Motion Blur (new optional Project and Material setting.)
  • New Tone Mapper with more filmic look and standardized parameters
  • Foliage Rendering optimizations, including occlusion culling support.
  • Hierarchical LOD System, for auto-clustering of actors and auto-merging of meshes/materials
  • Network Replays: Rewind support, and Live Time Scrubbing (see ShooterGame example.)
  • Web Browser UI Widgets for Unreal Motion Graphics (desktop platforms only)
  • Unreal Motion Graphics UI Editor: Many improvements (split screen support, animation workflows, device preview, full screen drag and drop.)
  • Foliage Editor UI has been redesigned to be easier to use
  • Paper2D: Tile Map Collision Authoring (Early Access)
  • Paper2D: 2D Editing mode with transform gizmo
  • Paper2D: Normal mapped sprites, and multiple textures per sprite
  • Plugin Creation Wizard (Experimental Preview). Create new editor plugins easily, thanks to Karolz on GitHub!
  • Global Editor Settings. Your window layout (and many other settings) is now remembered across all projects
  • Ctrl+Tab Window Switcher, to quickly navigate between any editor window or tab
  • In-world Component Editing: Per-instance Blueprint component property editing support
  • Blueprints: Many stability and workflow improvements. This was a major focus of 4.8 release.
  • Blueprint Graph Wire editing (move wires with Ctrl+click, easily reroute with double-click, alt+click to remove.)
  • New Procedural Mesh Component (Early Access), for easily creating 3D meshes at runtime using Blueprints or C++
  • Static Mesh Editing: Automatic Convex Collision generation has been greatly improved (V-HACD)
  • Many new features exposed to Blueprint Scripting, include all major Game Mode features.
  • Asset Size Mapper: Visualize memory footprint of game assets in an interactive tree map UI
  • Data Table Editor has been improved for faster iteration on spreadsheets

Known Issues List

This is a list of recently discovered bugs in our 4.8 Preview engine release that includes high priority bugs discovered by Epic, as well as all confirmed community-reported bugs. We will attempt to resolve critical bugs before final 4.8 release, other bugs that do not block development or have workarounds may be marked to be fixed in one of 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 latest bugs discovered with this preview release. This list will be periodically updated with new additions and to reflect which ones have been fixed internally, so be sure to check back!

Known Issues for 4.8 Preview 4

OPP-3371 If Preview build is made available while Launcher is running, cannot pass “Please Wait…” when downloading (workaround by restarting launcher)

UE-8770 Lighting needs to be rebuilt for content examples
UE-8881 Save error when adding additional functionality to Widget that is referenced in GameInstance
UE-11541 Editor crashes running out of static TLS storage limit
UE-11876 OnRep functions do not fire on client
UE-12935 Lightmass crash when building lighting in RenderTestMap
UE-13342 Crash occurs opening Test Map
UE-13346 Last moved widget in graph reorders to bottom of hierarchy
UE-13421 UMG widget is stuck in mouse down state after exiting Play session
UE-13846 Audio does not play in editor on Linux
UE-13902 StrategyGame black screen in Firefox browser
UE-13943 NavMesh generates 90 degrees rotated for custom collisions
UE-14101 Unable to build lighting on Linux
UE-14348 Long time to reach server using SSH
UE-14603 Windows executable from unified cooker crashes on launch
UE-14803 Android Java files constantly being rewritten triggering rebuilds
UE-14934 New Feature-‘Build game before launch’ fails to build
UE-15043 DeprojectScreenPositionToWorld has inaccurate behavior in VR
UE-15065 Inherited components in Child Blueprints cannot be dragged into Event Graph to access their variables
UE-15086 Incorrect Sampler Type of Normal Texture Samples for M_CobbleStone_Rough Material from Starter Content
UE-15095 Adding a key frame to curve editor in UMG adds multiple keyframes
UE-15147 Depth Fade Particles are not rendered on iOS
UE-15171 Collision Analyzer window does not render correctly if it is opened from console anywhere other than when in PIE mode using selected viewport.
UE-15182 Unable to create blueprint class from ‘All Classes’ tab with only keyboard input
UE-15268 Spawning a bp, setting location, and simulating physics in one string will cause Set Actor Location node to be ignored
UE-15271 Subcomponents of classes do not show up in BP hierarchy
UE-15275 Certain components created at Runtime appear to have unnecessary scene components
UE-15357 OnDragDetected fires off with a single click for 3D widgets
UE-15363 Under My Blueprints Right click Rename does not work on Mac
UE-15380 Game sounds only play during first PIE editor session for Linux project
UE-15384 Hover events do not fire off until after clicking when Set show mouse is set to true after game input was focus
UE-15388 Importing skeletal meshes with uniform scale >1 causes rotation in skeletal mesh editor to improperly register
UE-15395 16 bit PNG Texture rendering incorrectly in Material and UMG
UE-15432 Creating a new project from vault does not save default location
UE-15433 Separate Translucency for Particles Breaks when Scene Color is used
UE-15450 Cannot change collision on child components of blueprint in Details Pane
UE-15453 Cannot place static mesh in location if foliage mesh is already placed in same location
UE-15462 On Linux, FBX Import breaks content browser and RMB control in edior
UE-15463 Editor produces error when loading a level that references a blueprint in which a component has been deleted while in another level
UE-15466 German keyboard layout does not recognize keys ö,ü,^ in editor
UE-15479 “Set Animation Mode” creates multiple instances of AnimBP
UE-15480 Unable to use GetClass to set class for SpawnActor
UE-15506 Stacked Material Nodes become difficult to read
UE-15512 Using a generated timeline in blueprint causes an exception in engine code.
UE-15516 Pivot does not stay with grouped actors when surface snapping is enabled
UE-15545 Get Overlap Infos is not very descriptive and some data is not being exposed
UE-15564 “Play” node does not restart animation when triggered
UE-15572 Linux Editor crash upon opening
UE-15575 Crash while using a UFE custom profile to cook on Linux
UE-15593 Calling a parents function that is used in a child blueprint from a spawn actor from class node that is being called back in parent will cause an error
UE-15601 Sprite Based Particles in High End Mobile Metal Preview are FUBAR
UE-15626 World Outliner Sorting order ignores underscores for order
UE-15637 Editor crashes with 2 or more Clients when spawning in a Blueprint created from a Static Mesh using Blueprint/Add Script button
UE-15661 Incorrect Camera location in code First Person Template
UE-15663 Crash on Assigning Material to Element 1 in Reimported Static Mesh
UE-15681 ShaderCompileWorker crashes when compiling shaders on QA-Effects with a GTX480
UE-15682 Collision Boxes not set properly when using negative values
UE-15719 Regression: HTML5: VehicleAdvTemplate: Landscape material very on mountain “road”
UE-15753 Mouse buttons become depressed once Set Keyboard Focus is run on a 3D widget
UE-15755 Select Node not supported in AnimGraph, but still remains a selectable option
UE-15761 Using ‘Show Only Selected’ Option with Grouped Actors Selected in Viewport Still Hides Grouped Actors
UE-15771 Crash upon attempting to submit a level to source control after enabling Lock Read-only Levels
UE-15780 Live Node Previews are broken with Coordinates higher than UV0
UE-15781 UE4 crashes on Linux when exiting PIE using ESC key on Blueprints office
UE-15788 HeaderTool issue with comment format
UE-15795 Odd behavior when moving a large number of assets
UE-15821 Wires cannot be Ctrl + dragged off reroute nodes
UE-15831 10 or more Static Meshes set to Simulate Physics and Replicates Movement will crash editor with PIE set to 2 or more players
UE-15835 Editor becomes unresponsive after clicking off of a Widget when input mode is set to UI only
UE-15847 Unable to Compile Actor Blueprint with Tilemap Component
UE-15849 Top Down template TopDownController has Block Input enabled by default
UE-15859 Adding impulse to a Static Mesh Component that is not root of an Actor Blueprint does not replicate movement to Client
UE-15883 VR preview Crashes for Oculus Rift on 4.8 preview 3
UE-15891 Using Start Players as Spectators checkbox does not affect Player0
UE-15894 French AZERTY keyboard does not recognize ù, £, §, ^, _, ', or ² keys
UE-15903 [CrashReport] Lighting build triggers array out of bounds crash
UE-15909 Opening a level with a navmesh in standalone game crashes standalone .exe
UE-15929 Starter Content folders return to content browser after being manually deleted
UE-15939 HTML5 Engine Scalability set via C++ are not kept.
UE-15951 UMG crashes when “Use Selected Object from Content Browser” references wrong type of asset in style menu
UE-15955 Incorrect Camera location in BP First Person Feature Pack
UE-15956 Incorrect Camera location in C++ First Person Feature Pack
UE-15977 Packaging a game with Leap and Paper 2D plugins turned off will result in errors on launch of packaged game
UE-15991 [LandcapeMountains]-DebugCreatePlayer causes loss of function/control for player One
UE-16012 Errors when reorganizing marketplace assets into a project hierarchy
UE-16027 Editor not properly handling frame ranges for 60fps animations
UE-16028 Map disappearing from project
UE-16082 Tangents are flipped in sprite rendering
UE-16092 MAC: Crash reports & other saved files are stored inside Application Bundle, which is Read-Only for non-Admin users
UE-16113 Rare crash when accessing in game menu after loading into a zone
UE-16121 Foliage in editor tutorial broken
UE-16122 “Project World location to Widget position” node does not return correct screen position unless widget’s anchor point is set to top left
UE-16125 Copy/move does not work within same content browser window
UE-16126 Foliage Loses Dynamic Shadows from Moveable Point LIght at given Light to Mesh Height
UE-16128 OnOpening for ComboBox(string) fires off when ever widget is clicked not just when opening
UE-16133 Swarm Agent Local Host of Coordinator not showing up in Coordinator
UE-16140 First Person Game Mode isn’t set correctly for new default levels
UE-16142 Landscape Undo Causes Floating Foliage
UE-16144 Ctrl-Z does not function in Static Mesh Editor
UE-16150 Compiler error after changing class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing node, and reconnecting exposed variables
UE-16154 Assets Using SpeedTree in a material will render static shadows in Reflection Captures
UE-16158 Long texture streaming times on PS4 and Xbox
UE-16170 Setting scale in any direction breaks overlap events
UE-16171 Orange Screen when using VR preview mode with oculus rift

Awesome! Though launcher seems stalled while trying to download it for me.

–Had to restart launcher, all good now!

-is there a way to try shooter game and test new network demo? Currently, there is not an option to download that engine version. Can I just manually switch engine version on 4.7 download and try it or will there be pieces missing?


Great! I’m downloading and will soon report 30 new bugs I will find in 4.8 :wink: Your download servers are a bit overloaded.

Yayyyy :smiley:

Though launcher seems stalled while trying to download it for me.

Im downloading. with 3MByte/sec… But 5.7+ Gig is quite a chunk :slight_smile:

Thank you !! …fingers crossed for gearVR AA …just in time for last few days of Jam :smiley:

It’s here!!! can’t wait to try out to new foliage tools

Nice (y) :3333333333333333

Global Editor Settings. Your window layout (and many other settings) is now remembered across all projects

Finaly! Finaly! Finaly!

You guys rock! :smiley:

Thank you !! …fingers crossed for gearVR AA …just in time for last few days of Jam :smiley:

Just a reminder that these are not intended for development. They are known to be unstable with functionality that may not work as intended.

Wanted to make sure you’re aware of this before getting into a jam. :wink:

Hey guys,

just a quick heads up that users who had launcher opened when push went out will have to close and reopen launcher to get 4.8 preview build to start downloading.

  • B.

Cheer !!!
Good jobs.

Just a reminder that these are not intended for development. They are known to be unstable with functionality that may not work as intended.

Wanted to make sure you’re aware of this before getting into a jam. :wink:

I am already in a “Jam” :smiley: …I know what deal is; but a person can dream a little :cool:

I’m a happy camper!

Does this update include ‘late-latching’ technique for improved VR performance?

downloading now, awesome 5.5 jiggle bytes; giggle bytes. . . giga bytes. Jeez wake myslelf up. Whatever. To much beer in morning.
Awesome, Epic. More buttons to push!
Thank You!

Just finished downloading :slight_smile:

And of course its also time to check 4.9 on master branch :cool:

Amazing set of features guys! A lot of features I’m really interested in.

Global Editor Settings. Your window layout (and many other settings) is now remembered across all projects

Sir, can i fall in love with this feature?