In this video I show you how I did those trees with a simple trick to get the animated sunlight through the leaves. Thanks to UE4, you get really nice realtime animated dappled light effect... with no render time ! Enjoy.
The trees are made in 3ds Max with Grow FX, both available for free for 30 days, and the tree template is also free so no reason why you can't do this yourself !
Please let me know if you have any particular issues in the comments and I'll do my best to help!
Have fun !: )