yeah probably Google Translate is not a perfect tool
I am worried a bit about keeping the original lights and shadows. Finally it could result in more work, level design problems, and less unified look than removing them, and recreate by PBR shaders.
I think this unlit shader won't be perfect in many cases. Definitely good for fixed camera, but in case of rotating/moving the surfaces will have a flat feeling despite the detailed lighting and natural shadows. Or you need to go towards higher poly (of course lods can help to increase performance), because you cannot use normal, height, AO, specular, roughness etc maps. Maybe fine for ground what is normally not examined the player too much.
In UE4 there is a relatively new technique called distance field shadows to get hard shadows at object roots becoming softer on distance https://docs.unrealengine.com/latest/INT...wing/index.html what you can combine with cascaded dynamic shadowmapping. Moreover, in UE4 (maybe in Unity too) you can combine easily baked shadows (featuring cool indirect lights) with per object dynamic shadows (if not too many present in the scene).
Imo to approximate the forest photos you linked, you cannot use photo lights shadows at all, only if you recreate exactly the real environment in your scene, which will make your project enormous, but it would not result in realistic leaf rendering taking into account Sun and camera directions. I mean lights going through leaves, what I can make in UE4 easily but requires dynamic lighting and subsurface scattering. To get finally something like this: http://www.extremetech.com/extreme/18849...-games-graphics
Maybe you are right and you can do what you plan, but you have not convinced me yet.
