First - you need experience with the Actors - i will not explain why to do things, or how to set specific datas. Just give you a quick Guide to do this.
To actually do OTF (On-the-fly or live) terrain deformations you need 2 things:
an actor
a hook - in terms of something to activate the actor, which is i.e. in the Tech-Demo the baneling explosion
So let's take these little cute banelings and make their explosion look really dangerous (well not really - lol) Create a new map - whatever you like and size, i would advice you to edit the triggers so you see the whole map. (in techdemo i also have a 'place baneling on M4 click position' trigger) Place a baneling on your map. That's all you need to do with the map so far with Units. next go into your data editor (F7), and go to Actors Create a new Actors Object and choose ActorType: 'Terrain Deforming' (simple huh) ... First adjust some values like:
Blend Time - Time over which the deformation will be "animated"
Footprint - Shape of the Peak of your deformation (i prefer Creep Tumor as it is a circle)
height delta - the amount of height added/subtracted by the deformation
Influence range - Radius/size of deformation
next go into Events+ (Events Array) and add a new Event choose as
Msg Type: Effect
SourceName: Baneling - Suicide (Unit Damage) - or just until left appears Effect.BanelingU - can also be anything else of the baneling attack set
Action/Message: Create
that's all - you are done - launch map - select baneling, let it explode
ah yea here another demo i just recorded yesterday (this is not the demo)
