For everyone still exploring this branch, RTGI has been officially checked into dev-rendering (yay!):
Ray tracing global illumination. Currently disabled by default to evaluate performance and quality in WoodChuck. r.RayTracing.GlobalIllumination (enables RTGI, default = 0) r.RayTracing.GlobalIllumination.Denoiser (enables denoising, default = 1) r.RayTracing.GlobalIllumination.SamplesPerPixel (determines samples-per-pixel, default = 1) r.RayTracing.GlobalIllumination.MaxBounces (determines maximum number of diffuse bounces, default = 1) r.RayTracing.GlobalIllumination.EvalSkyLight (determines whether or not SkyLight can be hit with indirect diffuse, default = 0) r.RayTracing.GlobalIllumination.MaxRayDistance (maximum ray distance for diffuse and visibility rays, default = 1.0e27) Details here: https://github.com/EpicGames/UnrealEngine/commit/20588dd212b6d316da7221734d8819913010a6c0