What is this effect called and how to make something like this ?

Development Rendering
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1

I’m talking about the blue spell. I understand how to make the ball in the center but how do you do that thing on the ground to be aligned perfectly to the ground ?
An other example would be the green circles that appears when you try to cast ranged aoe spell in wow, gw2 etc

2

That is probably done with decals… or at least, how you could do it inside ue4.