Snippet Advanced Projectile Motion Experiment

13lade619

is now a game developer :)
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MAJOR UPDATE!! SYSTEMIZED!!

The purpose of this Snippet/Tutorial is to show you the results of the experiments I made
about advanced projectile motion,
more precisely creating an XY arc with a Z arc simultaneously.


90811Projectile.gif

System In action, but just movement.. no effects.
I used an arrow to show that the facing is constantly modified for aesthetic purposes.

Before we start, there are two people i want to thank because I based my codes from their calculations.
Vexorian > for his Caster System i used for the vertical arc
emjlr > for his Wild Axes spell i used for sideways arc

as you can see it currently only targets points for now... sorry?

Ok, here’s the new code.
Complete with config header

You can now use
“function ProjectileLaunch takes unit caster, location loc1, location loc2 returns nothing” to launch a projectile from another trigger to make things easier.

You can edit the main parameters on the “TheProjectile” trigger.
Check the “Sample” Trigger for an example.

* you can edit the function to add more parameters and make it a system though..

First piece... is the Projectile function which you can modify.
JASS:
library TheProjectile requires KLHV
//REQUIREMENTS : Kattana's Local Handle Vars, yes.. so old school.
//             :::::: the system must be in a trigger, not map header.
//             :::::::::::: name a library "KLHV" and it willl be ok.
//             : Dummy unit in the OE
//             : dummy.mdl in the imported models << very important, don't forget it.
//             : a triggering ability, change the condition below.

// use the function ProjectileLaunch takes unit caster, location loc1, location loc2 returns nothing
// configure other parameters below.
// you can edit the function to add more parameters and make it a system though..

//Configurables
globals
    private constant real Z1 = 100          // start loc z
    private constant real Z2 = 100          // end loc z
    private constant real ARC = 0.35        // same as OE, 0 to 1. affected by arcspeed.
    private constant real ARCSPEED = 1000   // rate at which the arc changes, low speed makes larger arc.
    private constant real ARCW = 300        // width of horizontal arc. increase or decrease.
    private constant real LA = 45           // launch angle. you can switch to -45 to launch in other direction.
    private constant real RSPEED = 0.05    // affects REAL speed of the projectile, no direct conversion to wc3 speed rate.
    private constant string MISSILE = "Abilities\\Weapons\\Arrow\\ArrowMissile.mdl"
endglobals

//=======================================================================================
//          NO TOUCHING???
//=======================================================================================

//The Struct.
struct projectile
    unit proj     
    real x1        
    real y1        
    real x2        
    real y2        
    real z1        
    real z2        
    real arcspeed   
    real arc       
    real face  
    boolean done    
    effect fx     
    
    real A         // from emjlr's Wild Axes spell
    real outx      
    real outy
    real s2        
endstruct

//=======================================================================================

//Movement Trigger, READ, but DONT edit.
function PMove takes nothing returns nothing
    local timer t = GetExpiredTimer()
    local projectile p = GetHandleInt(t,"pstruct")

    //Calculations from Vexorian's Projectile System.
    //     calculates the vertical arc.
    local real d = p.arcspeed*0.035
    local real od = SquareRoot(Pow(GetUnitX(p.proj)-p.x2,2) +  Pow(GetUnitY(p.proj)-p.y2,2))
    local real time = od / p.arcspeed
    local real zspeed = (p.z2-GetUnitFlyHeight(p.proj)+0.5*p.arc*time*time)/time

    //Calculataions from emjlr's Wild Axes spell.
    //     calculates the horizontal arc.
    local real b = 1.-p.A
    local location l

    // when the missile reaches endpoint.
    if( p.A < 0)then
        call ExplodeUnitBJ(p.proj)
        call DestroyEffect(p.fx)
        call SetUnitAnimationByIndex(p.proj,91)
        set p.done=true
    else    
        //VERTICAL ARC, from Vexorian 
        call SetUnitFlyHeight(p.proj,GetUnitFlyHeight(p.proj)+zspeed*.035,0)
        //Correcting animation, by Vexorian
        call SetUnitAnimationByIndex(p.proj,R2I(Atan2(zspeed,p.arcspeed)* bj_RADTODEG)+90) //Thanks infrane!

        //Corrective Facing >by me, 13lade619<
            set l = Location(p.x1*p.A*p.A+p.outx*2*p.A*b+p.x2*b*b, p.y1*p.A*p.A+p.outy*2*p.A*b+p.y2*b*b)
            call SetUnitFacingToFaceLocTimed(p.proj,l, 0)

        //HORIZONTAL ARC, from emjlr.
        call SetUnitX(p.proj,p.x1*p.A*p.A+p.outx*2*p.A*b+p.x2*b*b)
        call SetUnitY(p.proj,p.y1*p.A*p.A+p.outy*2*p.A*b+p.y2*b*b)
        set p.A = p.A-p.s2

    endif
        
    //Anti-Leaks..
    set t = null
    call RemoveLocation(l)
endfunction

//=======================================================================================
function AdProjectileLaunch takes unit caster, location loc1, location loc2 returns nothing
    // set necessary variables.
    local projectile p = projectile.create()
    local timer t = CreateTimer()

    set p.x1 = GetLocationX(loc1) 
    set p.y1 = GetLocationY(loc1) 
    set p.x2 = GetLocationX(loc2) 
    set p.y2 = GetLocationY(loc2)
     
    // NEEDED : starting and ending Z's.
    set p.z1 = Z1
    set p.z2 = Z2
    
    // facing angle and booelan, dont change.
    set p.face = Atan2BJ(p.y2-p.y1,p.x2-p.x1)
    set p.done = false
    
    // NEEDED
    set p.arcspeed = ARCSPEED    // affects the rate where the arc changes, lower generates bigger arc. calc by Vexorian.
    set p.arc = (ARC) * 8000 // vertical arc. change only within the (). calculation by Vexorian.
    
    set p.A = 1 // variable from emjlr.. dont change.
    
    //NEEDED 
    // you can change 555. higher is larger horizontal arc.
    // and change -45 to +45 to launch from the other side.
    set p.outx = p.x1+ ARCW *Cos(Atan2(p.y2-p.y1,p.x2-p.x1)+(LA))
    set p.outy = p.y1+ ARCW *Sin(Atan2(p.y2-p.y1,p.x2-p.x1)+(LA))
    // Affects the REAL SPEED of the projectile, lower is slower.
    set p.s2 = RSPEED
        
    //Starting movement, move to the PMove Function.
    set p.proj = CreateUnitAtLoc(GetOwningPlayer(caster),'e001',loc1,p.face)
    set p.fx = AddSpecialEffectTarget(MISSILE,p.proj,"origin")
    call SetUnitFlyHeight(p.proj,p.z1,0)
    call SetHandleInt(t,"pstruct",p)
    call TimerStart(t,.035,true, function PMove)

    // wait until the projectile hits.
    // by Vexorian. 
    loop
        exitwhen p.done
        call TriggerSleepAction(0)
    endloop

    // take care of everything...
    call FlushHandleLocals(t)
    call DestroyTimer(t)
    set p.proj = null
    call p.destroy()
endfunction
endlibrary

Second is the sample trigger for using it.
JASS:
function Trig_Sample_Conditions takes nothing returns boolean
    return GetSpellAbilityId() == 'A000'
endfunction

function Trig_Sample_Actions takes nothing returns nothing
    local unit caster = GetTriggerUnit()
    local location loc1 = GetUnitLoc(caster)
    local location loc2 = GetSpellTargetLoc()

    call AdProjectileLaunch(caster, loc1, loc2) //just the minor details though..
    
    call BJDebugMsg("POINT REACHED. Add Effects!")
    
    call RemoveLocation(loc1)
    call RemoveLocation(loc2)
    set caster = null
endfunction

//===========================================================================
function InitTrig_Sample takes nothing returns nothing
    set gg_trg_Sample = CreateTrigger(  )
    call TriggerRegisterAnyUnitEventBJ( gg_trg_Sample, EVENT_PLAYER_UNIT_SPELL_EFFECT )
    call TriggerAddCondition( gg_trg_Sample, Condition( function Trig_Sample_Conditions ) )
    call TriggerAddAction( gg_trg_Sample, function Trig_Sample_Actions )
endfunction

as you can see, i split the snippet into two because the place where you can add effects is pretty deep down in the first trigger. so i decided to turn the first part into a function.
 

Attachments

  • projectile.w3x
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Romek

Super Moderator
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I tested the map, without even glancing at the code.

- Uninitialized variable "l" used in PMove() (3-5 times)
- Uninitialized variable "l" used in Trig_projectile_Actions()
 

Romek

Super Moderator
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Oh, they aren't save errors. I'm using Grimoire, and it reports errors like that in-game.
It saved without problems, and I haven't looked at the code.

From a quick glance, I can't see where you're using an uninitialized variable. It seems like a problem with grimoire... o_O

Also, you may want to null those locations. :)
 
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> It seems like a problem with grimoire... o_O
No. He's removing uninitialized location "l" in the Trig_projectile_Actions() function. Same for the second one - location "l" isn't initialized in PMove() if p.A < 0.

And the random amount of times it shows the PMove() warning is caused by inaccurate TriggerSleepAction in the loop :p.
 

Viikuna

No Marlo no game.
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What if I want to use vector components, like velocityX, velocityY and velocityZ ?

How can I calculate the correct animation index, by using them?
 

13lade619

is now a game developer :)
Reaction score
398
What if I want to use vector components, like velocityX, velocityY and velocityZ ?

How can I calculate the correct animation index, by using them?

hehe... funny thing is..
i dont exactly know how the values work...

i just merged two different systems from two people in a chance to produce my desired effects...

i only know that this increases that or that.. lolz..
 

13lade619

is now a game developer :)
Reaction score
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NIce system but a bit specific and not easy to use.

yes.. frankly, it's not a system yet 'cause there arent any custom functions and its non configurable..
and the values are a bit guesswork for now..

maybe i'll be making it into a system when i learn more vJASS.
 

13lade619

is now a game developer :)
Reaction score
398
BUMPING.

new code up, systematized, config header, and can now be used in spells.
it's now consisted of 2 triggers.

and please let me know if there are errors with my library/globals.... maybe i missed something.
it's my first library type code.
 

~GaLs~

† Ғσſ ŧħə ѕαĸε Φƒ ~Ğ䣚~ †
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Effects should be independent on function calls? (Maybe?)

function ProjectileLaunch takes unit caster, location loc1, location loc2, string eff returns nothing
 
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