Im trying to make it so that when a bomb explodes it leaves a black mark on the ground

Is it possible to make it just add the sprite to the terrain skin? this way it will combine to the terrain and i can morph the ground below it

Why don't you use 'ent_decal' to place the sprite as a decal? What Ackenex version you use?

I found a cheaper solution I am still using A7 (I prefer c-script)

There is a demo with falling snow and terrain decal.
Try to find it.

@Devon that falling snow demo (weather.c in samples) is were I got the color check code from our other post. So if you can those functions in A7 then you can 'paint' the terrain like the snow.
You could read pixels from a source bmap and the paint them on to the terrain and even do a scaling of the area with a little logic. I'm sure this is not fast. lol