Firing straight forward

Could anyone tell me how to give a unit an ability that just makes it fire it's main attack (Artillery projectile) straight forward? This is employed in th15's Tank Commanders.

use a dummy ability like beserk, that has no target.....make it do nothing

create a dummy unit with the carrion swarm ability, edit it to how u like...

when a unit uses that ability make it so the dummy unit is spawned and uses that ability

youd do it so (unit order -- to use (undead-carrion swarm) at (unit(facingdegrees)

That would be right, but not what he means. Do the same thing, but instead of using Carrion Swarm, use a spell like Flame Strike as the ability.

Then do
"Unit-Add Ability (Cannon Shot)
"Unit-Order (unit name) to use (Flame Strike) at(Polar Coordinate (Unit Range) from (Position of (unit name) unit)
"Wait-(?) seconds
"Unit-Remove ability (Cannon Shot)

That will do it the way they did in that game.

Be sure to give the dummy unit Locust. People often forget that, making the result messy.

You can go to th15's website for a full tutorial on the Tank Commanders main cannon system. http://th15.dark-halo.com/war3

Thanks for your help! Now, could anyone help me another related thing?

What I'm hoping for is a shockwave that gets removed once it damages one target; I know I could just set the unit cap to 1, but I actually want the graphic to go away as well. Is this even possible?

Have you tried

A unit takes damage
Damage taken from ability comparison - shockwave
Animation - Stop all animation for ability being cast?

Not sure that's possible, but it's what I first though of.