Spreading Fire System

[TeroTron]

I'm making a RTS Map and i created this Siege Unit which can throw molotovs at trees and it will spread throughout the forest.
This Siege Unit throw molotov at a target tree
when it is destroyed/Burnt it will search 200 AOE for trees and burn it and the process repeats till the fire lasts
so, anyone got idea about how to do this?
and if possible please make it trigger

 

[Pinzu]

http://www.hiveworkshop.com/forums/2550444-post9.html

 

[TeroTron]

thanks man u helped me alot in just 1 day