Epic Games has announced the arrival of Unreal Engine 4.22 Preview 1. The significance of this development software update, now available for download via the Epic Games launcher or GitHub, is that it delivers support for real-time ray tracing.
Many PC enthusiasts will remember that various Unreal Engine powered demos have been shown off by Nvidia. The humorous Reflections Real-Time Ray Tracing Demo was released nearly a year ago featuring various Star Wars storm troopers including one with a very shiny suit. In Octiber we saw an update to the Lunar Landing demo with real-time raytracing added. Much more recently we saw the Project Sol Part 2 demo released at CES 2019. Both these demos have been created by developers with early access to tools from Nvidia and Epic Games. Now with Unreal Engine 4.22 Preview 1 these tools are coming to a much wider developer base.
The real-time raytracing support added to the Unreal Engine 4.22 Preview 1 appears to be quite comprehensive. In the full release notes, shared on the official forums, we can see that real-time raytracing forms a significant part of the rendering updates in v 4.22 Preview 1:
Real-Time Ray Tracing and Path Tracing (Early Access)
Added ray tracing low level support.
- Implemented a low level layer on top of UE DirectX 12 that provides support for DXR and allows creating and using ray tracing shaders (ray generation shaders, hit shaders, etc) to add ray tracing effects.
Added high-level ray tracing features
- Rect area lights
- Soft shadows
- Reflected shadows
- Ambient occlusion
- RTGI (real time global illumination)
- Geometry types: Triangle meshes: Static, Skeletal (Morph targets & Skin cache), Niagara particles support.
- Texture LOD.
- Denoiser: Shadows, Reflections, AO.
- Path Tracert
- Unbiased, full GI path tracer for making ground truth reference renders inside UE4.
Runtime Render Graph API
- Preview of the upcoming Render Graph API, only a small portion of the renderer has been converted.
Mesh Drawing Pipeline Refactor
- This refactor will make the upgrade process more time consuming than normal for licensees who have made custom modifications to private rendering code.
- Refactor adds auto-instancing at runtime and more efficient renderthread mesh drawing
In addition to the above there are a plethora of updates to the animation capabilities, audio, editor, dev tools, gameplay and scripting, mobile gaming, networking, Niagara visual effect editor, physics, sequencer, virtual production facilities, and AR/VR capabilities. As well as all the new features, Epic has quashed a multitude of bugs, as usual.
Finally, Epic Games reminds those that download Unreal Engine 4.22 Preview 1 for some testing must "keep in mind that Preview releases are intended only to provide a sample of what is going to be released in the update and are not production-ready". It is advised that you work on project copies with this preview release for now, and keep your working project files for the full release of v 4.22.