Archive notice: This article was originally published on February 13, 2019. Links and embedded videos are preserved as part of the historical record.
Porsche, Project Sol, and a Star Wars Stormtrooper in an elevator: so far there have been many demos of the new real-time raytracing features in Unreal Engine. With the new Preview 4.22 version, these can now also be tested yourself (in combination with an RTX graphics card).
You can add Preview 1 via “Add Versions” in the library area of the launcher. Alongside real-time raytracing functions, further new features such as Editor Utility Widgets, optimizations for Blueprints, Oculus Quest support and more are included. This is an early-access version that, according to Epic Games, you should not use for ongoing projects.
Real-Time Raytracing Features
The preview comes with an implementation based on UE DirectX 12 to support DXR. This fundamentally enables the creation and use of raytracing shaders (Ray Shader, Hit Shader, etc.) to add raytracing effects. Various “High Level Ray Tracing Features” have also been added.
(User test of real-time raytracing – until recently only in the dev branch on Github)
- Rect area lights, soft shadows, reflections, reflected shadows, ambient occlusion
- RTGI (real-time global illumination)
- Translucency, Clearcoat, IBL, Sky
- Geometry types: Triangle meshes (Static, Skeletal, Niagara particles support)
- Texture LOD
- Denoiser: shadows, reflections, AO
- Path Tracer
- and more
You can find all new features in the update notes.
Using Realtime Raytracing in UE 4.22
In order to use the real-time raytracing features after installing Unreal Engine 4.22 Preview 1, you need Windows 10 (Build 1809) and an RTX 20XX card with current drivers. In the properties of UE4Editor.exe, “-dx12” must also be added to the end of the file path. “Support Compute Skincache” and “Raytracing” can then be activated in the Unreal Engine project settings. You can find instructions here in the fourm.
