Automatic cannon aiming

Question

Hello,

I am making cannon in 2D, w$$anonymous$$ch is aiming at the target automatically by calculating angle of shoot... I used range of projectile equation, it worked, but it was more like a howitzer, so I upgrade it to cannon style aiming by Quaternion.inverse. Problem appeared, when there was a difference between Y positions of cannon barrel and the target. Problem is because, when it is in normal form (without Quaternion changes) it needed only a little additional angle to shoot at upper or lower object. Now, when cannon aiming from 0 - 45 degrees (before changes it was 90-45) angle adjust only a little, like before my upgrades, so it need more additional angle. I actually tried lot of ways in hope to fix it, but no one seems to work. Guys, can you help me, please? :)

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     void Update()
         {
             x = (Target.transform.position.x - BarrelEnd.transform.position.x) * XMultiply;
             v = AmmoSpeed - Plusser;
             v2 = v * v;
             g = Mathf.Abs(Physics.gravity.y);
             y = (Target.transform.position.y - BarrelEnd.transform.position.y);
     
             Angle = Mathf.Atan((v2 + Mathf.Sqrt(v2*v2 - g*(g*x*x + 2*y*v2))) / (g*x));
     
             transform.rotation = Quaternion.Inverse(Quaternion.Euler(0,0, Mathf.Rad2Deg*Angle -               90));
         }

Answer 1

@Vokyczech I created t$$anonymous$$s piece of code 3 years ago, but i t$$anonymous$$nk it`s still working.

var Target: Transform; var grenadePrefab: Transform; var fireRate = 10; var attackRange = 20.0; var Damping = 6.0; private var Distance : float; private var nextFireTime = 0.0; function Start () { Target = PlayerTransform.playerTransform; } function Update(){ Distance = Vector3.Distance(Target.position, transform.position); if (Distance < attackRange) { Fire (); } } function BallisticVel(Target: Transform, angle: float): Vector3 { var dir = Target.position - transform.position; // get target direction var h = dir.y; // get height difference dir.y = 0; // retain only the horizontal direction var dist = dir.magnitude ; // get horizontal distance var a = angle * Mathf.Deg2Rad; // convert angle to radians dir.y = dist * Mathf.Tan(a); // set dir to the elevation angle dist += h / Mathf.Tan(a); // correct for small height differences // calculate the velocity magnitude var vel = Mathf.Sqrt(dist * Physics.gravity.magnitude / Mathf.Sin(2 * a)); return vel * dir.normalized; } function ElevationAngle(Target: Transform): float { // find the cannon->target vector: var dir = Target.position - transform.position; // create a horizontal version of it: var dirH = Vector3(dir.x, 0, dir.y); // measure the unsigned angle between them: var ang = Vector3.Angle(dir, dirH); // add the signal (negative is below the cannon): return ang; } function Fire () { if (Time.time > fireRate + nextFireTime){ nextFireTime = Time.time; FireOneShot(); } } function FireOneShot () { var ang = ElevationAngle(Target); var shootAng = ang +15; //shootAng = Mathf.Clamp(shootAng, 0, 360); transform.eulerAngles.z = -shootAng - 15; var grenade: Transform = Instantiate(grenadePrefab, transform.position, transform.rotation); var shoot = BallisticVel(Target, shootAng); shoot = Vector3(Random.Range((shoot.x - 20),(shoot.x + 5)), shoot.y, shoot.z); grenade.GetComponent.<Rigidbody>().velocity = shoot; //BallisticVel(Target, shootAng); // pass the angle and the target transform }

Answer 2

Answer by Voky · Apr 17, 2016 at 06:53 PM

@nebikhero Thx, it´s finally working!!!

One last question: Have you any tip how to easily invert x position of aiming? Because the cannon shoot at the wrong side :D

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nebikhero · Apr 17, 2016 at 09:56 PM 1

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Voky nebikhero · Apr 18, 2016 at 05:13 AM 0

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Automatic cannon aiming

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