(Possibly) tricky ability question

[Corleone]

Hey,
I've been working on a map for some time and I want my units ( tanks ) to have an ability to fire one bullet. I tried basing it off Carrion Swarm, but then the bullet can move through walls, and doesnt disappear when it hits an enemy. So, since I hardly have any experience with abilities, I ask for your help.
The ability should:
- Not be visible, nor deal any damage after it collides with a wall
- Disappear when it hits an enemy
Optional
- If two bullets collide, they both explode // destroy eachother.

What should I base it on, and how should I trigger it ( if necessary )?

 

[Some1Sneakin]

Sorry but it i dont think if all that is possible atleast not with that it destroys when it hit a wall and it explodes when hit another.

Maybe something of that is possible but im not sure i will see if it can get it to work

 

[hi_im_bob]

You might want to look at how it was done in Elimination Tournament.

 

[Corleone]

I just got an idea, actually. Could it be possible to determine the angle between the casting unit and the target of the ability being cast? Then I could create a unit and order it to move towards that direction, and give it a constantly turned on immolation with 9999 dps. That would also make it possible to kill it when it exits the "arena" and when it collides with another bullet; because I could give it 1 hp. Anyway, anyone got an idea on how to figure out what the firing angle is and how to make the unit move towards that point?

 

[hi_im_bob]

Maybe this?

Unit - Create 1 Footman for Player 1 (Red) at (Center of (Playable map area)) facing (Facing of (Triggering unit)) degrees

 

[Corleone]

Well, i know how to make the bullet, but the hard part is to make it move in a specific direction. The only way I can think of to do this is to make 360 region ( one for each facing-angle degree ) but making that would just suck..

 

[AceHart]

> Could it be possible to determine the angle between the casting unit and the target of the ability being cast?

Set myRealVariable = Angle between points.

 

[Corleone]

Well, I tried using this trigger, but the bullet wouldn't actually move ( so setting the new target didn't really work ). How can I fix this? Should I just make it 2 If//Then//Else statements, or edit something else? I probably made it way more complicated than it should be

Triggered Fire
    Events
        Unit - A unit Begins casting an ability
    Conditions
        (Ability being cast) Equal to Fire! 
    Actions
        Set FireTarget = (Target point of ability being cast)
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
            If - Conditions
                (Y of FireTarget) Less than (Y of (Position of (Triggering unit)))
            Then - Actions
                Set BulletTargetY = (Point(0.00, ((Distance between (Point(0.00, (Y of FireTarget))) and (Point(0.00, (Y of (Position of (Triggering unit)))))) / 5.00)))
            Else - Actions
                Do nothing
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
            If - Conditions
                (Y of FireTarget) Greater than (Y of (Position of (Triggering unit)))
            Then - Actions
                Set BulletTargetY = (Point(0.00, ((Distance between (Point(0.00, (Y of FireTarget))) and (Point(0.00, (Y of (Position of (Triggering unit)))))) x 5.00)))
            Else - Actions
                Do nothing
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
            If - Conditions
                (X of FireTarget) Less than (X of (Position of (Triggering unit)))
            Then - Actions
                Set BulletTargetX = (Point(((Distance between (Point((X of FireTarget), 0.00)) and (Point((X of (Position of (Triggering unit))), 0.00))) / 5.00), 0.00))
            Else - Actions
                Do nothing
        If (All Conditions are True) then do (Then Actions) else do (Else Actions)
            If - Conditions
                (X of FireTarget) Greater than (X of (Position of (Triggering unit)))
            Then - Actions
                Set BulletTargetX = (Point(((Distance between (Point((X of FireTarget), 0.00)) and (Point((X of (Position of (Triggering unit))), 0.00))) x 5.00), 0.00))
            Else - Actions
                Do nothing
        Set BulletTarget = (Point((X of BulletTargetX), (Y of BulletTargetY)))
        Unit - Create 1 Bullet for Player 12 (Brown) at (Position of (Triggering unit)) facing BulletTarget
        Set Bullet = (Last created unit)
        Unit - Order Bullet to Move To BulletTarget
        Wait until ((Distance between (Position of (Triggering unit)) and (Position of Bullet)) Greater than or equal to 40.00), checking every 0.10 seconds
        Unit - Order Bullet to Night Elf Demon Hunter - Activate Immolation
        Custom script:   call RemoveLocation ( udg_BulletTarget )
        Custom script:   call RemoveLocation ( udg_BulletTargetX )
        Custom script:   call RemoveLocation ( udg_BulletTargetY )

 

[AceHart]

"Point with polar offset" is your friend.

Set myPoint = Position of (Casting unit) offset by 800 towards (Angle from (Position of (Casting unit) to Position of (Target point of ability being cast))
Unit - Order Bullet to move to myPoint


Don't use "begins casting" in triggered spells. Go with "starts the effect of".

 

[Corleone]

Well, for some reason, the bullet travels a random distance now. Sometimes it goes through the entire map ( as intended ) and sometimes it just stops for no reason.
Trigger :

Fire Target
    Events
        Unit - A unit Starts the effect of an ability
    Conditions
        (Ability being cast) Equal to Fire! 
    Actions
        Set FireTarget = (Target point of ability being cast)
        Set FireAngle = (Angle from (Position of (Triggering unit)) to FireTarget)
        Set BulletTarget = ((Position of (Triggering unit)) offset by 1000.00 towards FireAngle degrees)
        Unit - Create 1 Bullet for Neutral Hostile at (Position of (Triggering unit)) facing BulletTarget
        Set Bullet = (Last created unit)
        Unit - Order Bullet to Move To BulletTarget
        Wait 1.00 seconds
        Unit - Order Bullet to Night Elf Demon Hunter - Activate Immolation
        Custom script:   call RemoveLocation ( udg_BulletTarget )
        Custom script:   call RemoveLocation ( udg_FireTarget )

 

[AceHart]

There's always a reason

Like, the point is outside the playable map.
Or it's in the middle of a doodad.
It's in deep water.
...


You could try to test for the pathability of that point.

Alternatively, remember the direction it needs to go, and use a periodic trigger or timer to move it in smaller steps.

I would also activate immolation right after creation, then order the move, to remove that "wait".

 

[Corleone]

There's always a reason

Like, the point is outside the playable map.
Or it's in the middle of a doodad.
It's in deep water.
...


You could try to test for the pathability of that point.

Alternatively, remember the direction it needs to go, and use a periodic trigger or timer to move it in smaller steps.

I would also activate immolation right after creation, then order the move, to remove that "wait".

Well, it could be outside the playable map area, so I think Ill go for the periodic trigger system. It cant be in the middle of a doodad or in deep water, because the map has no doodads or water ( just a very, very simple arena ). Also, I didn't activate immolation right after creation, in case the unit that fires the bullet is still too close to the bullet, and kills himself. Ah well, time to remake the trigger