DirectX Graphics Samples /Engine/Source/ThirdParty/Windows/D3DX12/ There are two files that are currently checked into the engine under /Engine/Source/ThirdParty/Windows/DirectX/ which are not actually part of DirectX and are covered by a different license.(They were originally added in the DX12 Microsoft partner branch). These are header files that will be compiled into the engine. https://github.com/microsoft/DirectX-Graphics-Samples/blob/master/LICENSE/ Licensees Git P4 \UE4\Engine\Source\ThirdParty\Licenses\DirectXGraphicssamples_License.txt