Epic has just announced Unreal Engine 4.22 Preview 1 is now available to download, its headline feature being the first support for real-time ray tracing.

Developers will now be able to get hands-on with the ray tracing tech and begin implementing it in games built on Unreal Engine 4. This is the first implementation of DXR support and is considered an early access version that could be a little rough around the edges.

Unreal Engine 4 was used as the showcase for a lot of the early ray tracing tech demos, including the Star Wars-themed Reflections Real-Time Ray Tracing Demo that impressed us so much last year. Epic’s engine uses Microsoft’s DXR framework in conjunction with Nvidia RTX technology to render the ray-traced reflections which, at the time, we thought was years from becoming reality.

UE4 was also used for the recent Project Sol ray-tracing cinematic demos used by Nvidia, the latest of which was showcased at CES 2019 in January.

According to the update notes, the follow DXR rendering updates have been added to UE4.22:

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
    • Reflections
    • Reflected shadows
    • Ambient occlusion
    • RTGI (real time global illumination)
    • Translucency
    • Clearcoat
    • IBL
    • Sky
    • 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.

The upshot of all this is the floodgates are now open for ray-traced games developed through Unreal Engine 4. At the moment only Battlefield V (Ray Traced Reflections) and Metro Exodus (Ray Traced Global Illumination) feature ray tracing effects, developed in the proprietary Frostbite 3 and 4A Game Engines. The uptick has been fairly slow as it's a fairly niche market to cater towards, although this update should go a long way to lowering the barriers and encouraging other developers to make use of the tech that's currently exclusive to Nvidia Turing GPUs.

If you’re in the business of messing around with Unreal Engine 4, all you need to do get started with Unreal Engine 4.22 Preview 1 is head to the library section in the Epic launcher and select ‘Add Versions’, then choose 4.22 Preview 1. Simple.