Moving Cloud Shadows on Terrain possible? ( fastest way )

[kadir.basol]

Hello , we have successfully done new terrain work but we want to make terrain more attractive.

I've seen that on Command and Conquer Tiberium Wars,

 

 

here they have made cloud shadows moving on ground.

How can we do it on unigine fastest way ?

 

what about decals ? we will have to move decals on ground ?

 

also more modern one sample here :

[frustum]

Shadow surface of ObjectSky performs ground shadow effect.