Speedtree : Whether you’re using UE4 Custom or UE4.3 Subscription, the integration of SpeedTree® for Games offers a full range of SpeedTree features, including amazing performance, a highly versatile modeling app, lightmap-ready UVs, scalable wind effects, seamless LOD and more.
Substance Plugin :With a full integration in Unreal Engine 4, Substance Engine makes the creation of next-gen textures a seamless experience for even the most ambitious of game developers. This integration comes as a free plugin available for all Unreal 4 licensees.
If you’re using Unity,you can have AAA tree editing tools by subscribing to the SpeedTree Modeler, available for Windows and Mac OSX.