Unreal can do what you are describing. In the 4.7 release the shader for foliage got improved and we are getting some incredible grass related things in 4.8 and beyond.
There is even the nvidia Turf plugin in the works (so I heard) which is the same as that plugin for unity you mentioned. Only it looks soooo much better and is a wildly accurate simulation of grass behaviour.
Then there is speedtree which can easily make randomly generated patches of individual (or not) blades of grass. and it is affected by a wind actor:)
Then there are techniques for making grass “by hand”.
I mean… the foliage tool built into unreal engine can do all of the things you describe… even more than you described…the only thing you need is a grass mesh wih the material…
For that you need texturing and modelling knowledge or speedtree if you are lazy like me… How the grass mesh looks is up to you…
What you probably want is something that will give you all the assets already made, so you can just place them in the level… There are asset packs for that, but
there aren’t many… plus it will be better if you learn other software and let the creative juices flow by making it yourself.
Now when you say there aren’t many good examples of good grass in ue4… well there aren’t many in unity either… It’s mostly up to the skill of an artist to make good foliage, and up to techies to make it run smoothly.
As with all game developement aspects… it’s a game of balance… of what you could do with a pro artist to what is actually usable in gameplay…
I found this guy on the forums who released a great grass pack recently. It’s great for seeing how the meshes actualy look and how the materials are done.
Here are some more examples of grass inside unreal engine. Plus the amount will rise in the coming months due to the release of 4.7 and the upcoming release of 4.8.
this one is quite old so this guy could improve it even further
and then there is this… when we get this I’ll explode