Keeping a units z coordinate steady.

[AdamGriffith]

I am working alot with projectile motion at the moment in my map and so far I dont seem to be able to make a projectile fly at a certain height no matter what the terrain is like.

Let me attempt to explain with rubbish drawings:

Correct:

-------------------------------------------

-----\            _____/--------------------\
\       \          /                                      \
\        \_____/

Incorrect:

-----\            _____/--------------------\
\       \          /                                      \
\        \_____/                                        

-----\            _____/--------------------\
\       \          /                                      \
\        \_____/

EDIT:
Drawings gone a bit funny but you can see what I mean.

 

[saw792]

Perhaps you could use GetLocationZ at the point where the projectile starts, then every interval set the flying height of the unit to

(GetLocationZ(initialLoc) - GetLocationZ(currentLoc)) + Height

That is completely untested.

 

[The Undaddy]

function GetUnitZ takes unit u returns real
    local location l = GetUnitLoc(u)
    local real z = GetLocationZ(l)
    if u != null then
        call RemoveLocation(l)
        set l = null
        return z + GetUnitFlyHeight(u)
    endif
    set l = null
    return 0.
endfunction

function SetUnitZ takes unit u,real z returns nothing
    local location l = GetUnitLoc(u)
    if u != null then
        //call UnitAddAbility(u,'Amrf')
        //call UnitRemoveAbility(u,'Amrf')
        call SetUnitFlyHeight(u,z - GetLocationZ(l),0)
        call RemoveLocation(l)
    endif
    set l = null
endfunction

The second function will set the unit's Z absolute from the 0 height.

 

[AdamGriffith]

Could you please post a "movement" trigger for that.
So like a timer callback function to periodically move the unit keeping the flying height constant?
I have tried but it didnt seem to work.

 

[saw792]

function Callback takes nothing returns nothing
  <Recover Struct>
  local real initz = data.initz
  local location l = Location(data.x, data.y)
  local real curz = GetLocationZ(l)
  set x = ...
  set y = ...
  set z = HEIGHT + (initz - curz)
  call SetUnitFlyHeight(..., z, 0)
endfunction

That's using my (still untested) method. Using The Undaddy's method (which I suspect is the same as mine but I haven't read properly) you would simply call SetUnitZ(unit, z) every callback.

 

[Viikuna]

And you need to use ground units, because Blizzards flying height smoothing thingie makes flying units move weirdly.

Just dont forget to add&remove 'Amrf'

 

[The Undaddy]

Could you please post a "movement" trigger for that.
So like a timer callback function to periodically move the unit keeping the flying height constant?
I have tried but it didnt seem to work.

function callback takes nothing returns nothing
    local WonderStruct data = GetTheStruct()
    call SetUnitZ(data.u,data.Height)
endfunction

Simple as that