October 3, 2014

Unreal Engine 4.5 Preview Notes

By Brandon Sieprawski

The upcoming 4.5 release includes eagerly-awaited features such as animation retargeting, automatic C++ hot reload, light map UV generation and streaming video textures. New real-time ray traced soft shadows allow for beautifully lit dynamic scenes, and screen-space subsurface scattering enables very realistic skin materials. Finally, creating user interfaces has never been easier now that Unreal Motion Graphics is ready to use!

This release also contains a huge number of usability and learning enhancements, an all new tutorial system, and new game templates for Advanced Vehicles and Twin Stick Shooters.

More than 40 features and improvements were contributed by our amazing community of developers. We would like to extend our gratitude the contributors to this release.

3dluvr, Allegorithmic , Cameron (Alters), Jefferson Pinheiro (Ixiguis), Kyle Rocha (kylawl), Luna (PSG-Luna), leobenaducci, Mathias L. Baumann (Marenz), Martino Giovanelli (Hurricane86), Moritz Wundke (moritz-wundke), Pierdek, Rama (EverNewJoy), Ryan Ingram (ryani), Robert Wallis (robert-wallis), Rick Yorgason (Skrapion), Roy (Shammah), Salamanderrake, Sam Clegg (sbc100), Steve Anichini (solid-angle), Shaun Hedrick (triplefault), Thomas Mayer (tommybear), Tim Donks (timdonks), Temaran, Vitaly Ogoltsov (vogoltsov), Zachary Burke (error454)

Major New Features


Ray Traced Distance Field Soft Shadows

There is a new dynamic shadowing method which works by tracing a ray through mesh distance fields to the light. This allows for soft area shadows with sharp contacts!

Ray Traced Distance Field Soft Shadows

Here’s a directional light with ray traced soft shadows. The self-shadowing in the distance is still detailed, and long shadows get softer.

Trace Distance Screen 2

Directional lights can combine ray traced shadows with the usual cascaded shadow maps (CSM) to get the best of both approaches. Only nearby shadows are computed with CSM in this screenshot.

Trace Shadows 3

Point and spot lights work too. ‘Source Radius’ is used to control how large the light source is and therefore how large the shadow penumbras are.

These distance fields are the same data used by the Distance Field Ambient Occlusion feature. You can enable it with ‘Use RayTraced DistanceField Shadows’ on a light, in projects which have the ‘Generate Mesh Distance Fields’ project setting enabled.

Screen-space Subsurface Scattering

A new “Subsurface Profile” shading model has been added! You can use subsurface scattering to create realistic skin materials and other awesome effects.

subsurface Scattering

Left: no subsurface scattering, Middle: realistic settings, Right: exaggerated settings

Dynamic Shadows on Mobile

Dynamic shadows for movable directional lights are now supported on mobile platforms! Shadows are rendered using cascaded shadow maps with up to two cascades.

Unreal Motion Graphics (GUI Designer)

Unreal Motion Graphics is now ready to use and available by default! Simply create a new “Widget Blueprint” and start designing your UI. Of course, new features and improvements are still being added daily.

GUI Designer

UI Render Transforms

Widgets in UMG and Slate can now be translated, rotated, scaled, and sheared!

UI Render Transforms

UI Styles

We now allow styling to be done completely inline for a widget’s definition. This allows users a much greater control over how widgets look without needing to clutter up their project with several dozen style variations. Styles can now be changed in game, allowing dynamic material instances to be used on any UI!

UI Styles

UI Animation

UMG now includes more robust animation support.

  • Multiple animations can be created for each widget


  • Animations can be controlled at runtime in your widget’s blueprint graph


  • Keys can now be added to animations automatically via the details panel


UMG Animation

UI animations can be controlled in the widget blueprint graph. This is an example of playing an animation when a widget is hovered.

Animation Blueprint Example

DPI Scaling

Unreal Motion Graphics now supports automatic scaling for resolution-independent UI. We now provide default DPI scaling rules for all games. You can configure this in your project’s Rendering settings.

DPI Scaling


Automatic C++ Hot Reloading

Unreal Engine now automatically “hot reloads” your C++ gameplay code after you compile in Visual Studio or Xcode!

C++ Hot Reload

No need to shutdown the editor while you’re working. Just compile your gameplay code normally from Visual Studio or Xcode, and the engine will apply your C++ changes instantly.

Full Game C++ Hot Reload

You can now compile any type of game C++ code without even restarting the editor, and your changes will be applied live! Even adding whole new classes or properties is supported.

Full Game Hot Reload

Sample Content

Advanced Vehicle Template

The new Advanced Vehicle template shows off a vehicle with double wishbone suspension, and a test track with terrain and many ramps and loops! It also works great with a VR headset.

Advance Vehicle Template

Twin Stick Shooter Blueprint Template

The new Twin Stick Shooter Blueprint template is a perfect starting point for creating fast-paced, top-down shooter games!

Twin Stick Shooter

It’s a simple template for a Twin Stick shooter where one joystick is used for movement and the other is used to fire in any direction

Artist Template Map

A new map is available in the template starter content which provides artists a testing area to try out different lighting setups and see how their content is affected.

Artist Template


Animation Retargeting System

The new Animation Retargeting System allows you to convert animations between different skeletons using the humanoid rig!

Animation Retargeting Animation Retargeting System screen 2

Example Video: shows animation starter pack converted for another skeleton.

Once you have set this up, you’ll be able to convert animations between any skeleton that uses the same rig.

Media Playback and Capture

Video Textures (Media Framework)

The new Media Framework allows you to play streaming video on UI widgets and textured objects in your levels!

Video Textures

Video Textures 2

Check out our forum post about this new feature.

OpenEXR Frame Capture

You can now save rich frame data including HDR colors and 16-bit pixel depth into an OpenEXR file. This is really useful for offline compositing work.

Open EXR Frame Capture

Project Creation

New Project Creation Window

The New Project window has been redesigned to simplify the process of creating new projects!

New Project Creation Window

Target Hardware Selection

You can now select the type of hardware and devices you want to support, and the engine will choose optimal settings for the best player experience! This can be set when creating your project in the New Project window or in the Project Settings under Target Hardware.

Project Target Hardware

Learning Resources

In addition to new videos and new written documentation, there are major updates to how you can learn about how to use the editor and access documentation right when you need it!

New Tutorial System

The tutorial system has been completely overhauled in order to provide a more immersive experience!

New Tutorial System

There are no more popup windows. (Yay!) Unobtrusive text bubbles overlaid on the editor now walk you through interface elements and various features. The editor will alert you about tutorials you haven’t tried, but it never forces you to view anything.

No More Pop ups

Once you have decided to take a tutorial, you can right-click to see other navigation options (or click the combo arrow in the top-right of the content bubble)

Tutorials Browser

There is a fancy new Tutorials Browser that provides easy access to all of the tutorials

Tutorial Browser

Tutorials can be accessed from either the Help menu or by clicking the new Tutorials icon in the top-right of the editor.

Tutorials Blueprints

Tutorials are actually now built as Blueprint assets. This means you can create your own in-editor tutorials to include with content published to the Marketplace!

Tutorial Blueprints

Tutorials you create will automatically be visible in the new Tutorial Browser UI.

Improved In-Editor Help

Instant Online Help

You can type into the new Online Help box and the editor will gather as many helpful resources as we can find from the internet.

Instant Online Help

Tutorials, documentation, community wiki, and AnswerHub pages are now all accessible from here! Note: We’ve moved the in-editor debug console. You can now press the tilde (~) key to summon the console anywhere within the editor!.

New Help Buttons

With lots of new documentation anchors, it’s easier to jump directly to reference documentation as you need it in the editor!

New Help Buttons

Documentation Actors

New documentation actors have been added to sample content that links you to helpful documentation pages. Check out the updated Content Examples project that includes lots of new help links!

Documentation Actors

Documentation Nodes

Documentation nodes provide the ability to display documentation snippets in Blueprint graphs. This means you can embed text and images in your graphs to provide information that goes above and beyond the usual comment blocks!

Documentation Nodes

New Help Tool-tips

Lots of detailed tool-tips have been added all over the editor. Material nodes, placeable actors and blueprintable classes now all have rich help when you hover over them with Ctrl+Alt held down.

New Help Tool Tips


The Unreal Engine documentation now features an updated look which improves readability! In addition, we added search term suggestions to the front page to help you quickly find the topics you are looking for.

Video Tutorial System

The documentation now includes a video system for finding and viewing all of our video tutorial series! Everything is organized into categories and videos can easily be viewed as an entire series.

Video Tutorials

Introduction to The UE4 Editor

See the complete list of updates here!