LogInPacks with high-resolution models and textures of trees, rocks, debris, plants and more.
MAWI United is a CG and VR production studio that offers high-end computer animations and software development for TV commercials, visual effects for film, cinematics, trailers for video games, pipeline development and real-time 3d engine rendering. But there is one more thing that might interest you. The studio has amazing packs for Unreal Engine 4 users with high-quality content.
High resolution models and textures of trees, rocks, debris, plants and more. All assets with full sets of LODs, tweaked for maximum performance at highest photo realistic quality. The packs are all about massive forests. There is a large variation of fully setup foliage actors. Also, the packs feature fully paintable ground materials that can be easily customized.
Right now the studio is working on a Redwood Forest pack that can lead you to the creation of your own Endor. You can follow the progress here. The pack should be ready in 3-4 weeks.
You can find all the packs from the studio here. The packs are a bit pricey, of course, but they are definitely worth it.