probably already discussed.
Are there plans to enable Nvidia RTX kernel in UE?

best regards

“Now, leveraging the efforts of several technology companies, support for Microsoft’s DXR API and ray-traced area light shadows will be available in the main branch of Unreal Engine 4 by the end of 2018. Epic expects to release binary support for these features in Unreal Engine 4.22, with more features to follow as they become production-ready.”…validated=true