Use a vector3 position to calculate where a bomb falls

Seems like I'm getting somewhere!

Thanks to your effort, I've understood my mistake. First:

• I've been trying to modify the direction of my mortar dynamically, meaning that I was trying in my script up above to change the direction in mid-air; this was NOT intended and assuredly not in my concept.

• Reading both of your comments allowed me to understand that it was not my cannonball which I needed to modify, but the cannon which instantiate the ball.

So I've applied your script to my cannon. Although things seem to improve, it doesn't quite work well. Before, the bomb would spawn behind my cannons and would not move; now they spawn at the right place, but with no velocity whatsoever. $$anonymous$$eh.

Here's the script of my canon (corrected):

using UnityEngine; using System.Collections;

public class $$anonymous$$ortarGun : $$anonymous$$onoBehaviour { public Transform gunTip; public Transform target; public GameObject mortar; public GameObject name; public float fireRate; private float shotTime = 0.0f; public float shootAngle;

 void Update () 
 {
     shotTime += Time.deltaTime;
     
     if(shotTime >= fireRate)
     {
         if(!(name.GetComponent("Tower") as Tower).canAim)
         {
             GameObject cannonBall = Instantiate(mortar, gunTip.position, Quaternion.identity) as GameObject;
             cannonBall.rigidbody.velocity = BallisticVelocity(target, shootAngle);
             shotTime = 0.0f;
         }
     }
 }
 
 Vector3 BallisticVelocity(Transform target, float angle)
 {
     Vector3 dir = target.position = transform.position; // get Target Direction
     float height = dir.y; // get height difference
     dir.y = 0; // retain only the horizontal difference
     float dist = dir.magnitude; // get horizontal direction
     float a = angle * $$anonymous$$athf.Deg2Rad; // Convert angle to radians
     dir.y = dist * $$anonymous$$athf.Tan(a); // set dir to the elevation angle.
     dist += height / $$anonymous$$athf.Tan(a); // Correction for small height differences
     
     // Calculate the velocity magnitude
     float velocity = $$anonymous$$athf.Sqrt(dist * Physics.gravity.magnitude / $$anonymous$$athf.Sin(2 * a));
     return velocity * dir.normalized; // Return a normalized vector.
 }

} As you can see, the canon does the job of instantiating the cannonBall. But there's a twist: I used to add some properties to my mortar with which I played. Those were :

void Start () 
    {
        rigidbody.AddForce(transform.forward * force, Force$$anonymous$$ode.Impulse);
        rigidbody.AddForce(transform.up * force, Force$$anonymous$$ode.Impulse);
        rigidbody.AddTorque(torque, Force$$anonymous$$ode.Force);
    }

If I remove them, the cannonBall no longer move with velocity, just falls softly in front of the cannon...

You must not apply any other force to the cannonball, or it will never reach the target! The cannonball is just a rigidbody driven by initial velocity and gravity - remove that code!
Your script actually doesn't work because you made a typo in the first BallisticVel line (changed a - signal to =). But there's another problems: you're instantiating the cannonball at gunTip, but the calculation is being done based on transform.position - unless the script is attached to gunTip, the result will be wrong.
To avoid this problem, I changed the function to use gunTip.position. I also fixed the typo, and made the cannonball be destroyed after 10 seconds (to avoid a scene crowded with lost cannonballs). That's the result:

using UnityEngine; using System.Collections;

public class $$anonymous$$ortarGun : $$anonymous$$onoBehaviour { public Transform gunTip; public Transform target; public GameObject mortar; public GameObject name; // name is a GameObject property - you should rename this variable public float fireRate; private float shotTime = 0.0f; public float shootAngle;

 void Update () 
 {
     shotTime += Time.deltaTime;
     
     if(shotTime >= fireRate)
     {
         if(!(name.GetComponent("Tower") as Tower).canAim)
         {
             GameObject cannonBall = Instantiate(mortar, gunTip.position, Quaternion.identity) as GameObject;
             cannonBall.rigidbody.velocity = BallisticVelocity(target, shootAngle);
             Destroy(cannonBall, 10); // cannonball disappears after 10 seconds
             shotTime = 0.0f;
         }
     }
 }
 
 Vector3 BallisticVelocity(Transform target, float angle)
 {
     Vector3 dir = target.position - gunTip.position; // get Target Direction
     float height = dir.y; // get height difference
     dir.y = 0; // retain only the horizontal direction
     float dist = dir.magnitude; // get horizontal distance
     float a = angle * $$anonymous$$athf.Deg2Rad; // Convert angle to radians
     dir.y = dist * $$anonymous$$athf.Tan(a); // set dir to the elevation angle.
     dist += height / $$anonymous$$athf.Tan(a); // Correction for small height differences
     
     // Calculate the velocity magnitude
     float velocity = $$anonymous$$athf.Sqrt(dist * Physics.gravity.magnitude / $$anonymous$$athf.Sin(2 * a));
     return velocity * dir.normalized; // Return the velocity vector.
 }

}

Wow... it works! Thanks a lot ^^ Now I've got issues with my targetting system, but hey, at least I've got something :) Thanks again!

That's a nice idea you got there.

I've done something similar based on a class project we made a few weeks ago, using what you just suggested:

using UnityEngine; using System.Collections;

public class $$anonymous$$ortar : $$anonymous$$onoBehaviour { public float force; public Vector3 torque; public GameObject explosion; public Transform target; public float speed; public Transform guntip; public AnimationCurve curve;

 private Vector3 departPos;
 private Vector3 destination;
 private float currentTime = 0.0f;
     
 void Start () 
 {
     //Destroy(gameObject, 5.0f);
     
     rigidbody.AddForce(transform.forward * force, Force$$anonymous$$ode.Impulse);
     rigidbody.AddForce(transform.up * force, Force$$anonymous$$ode.Impulse);
     rigidbody.AddTorque(torque, Force$$anonymous$$ode.Force);
     
     departPos = guntip.position;
 }
 
 void OnCollisionEnter(Collision collision)
 {    
     foreach(ContactPoint cp in collision.contacts)
     {
         if(cp.otherCollider.gameObject.tag == "Floor")
         {
             Instantiate(explosion, collision.contacts[0].point, Quaternion.identity);
             Destroy(gameObject);
         }
     }        
 }
 
 void ApplyDamage()
 {
     
 }
 
 void Update()
 {
     currentTime += speed * Time.deltaTime;
     
     destination = target.position;
     
     transform.position = Vector3.Lerp(departPos, destination, curve.Evaluate(currentTime));
 }

}

But it does not work. $$anonymous$$y mortar appears BEHIND the canon and does not move...