[Solved]Targeting ball ?

Unity Engine
1

I got this script from website. It works but need some improvement. I need to change the power of shoot. In this script there is a range “_angle” but it’s not what i want. I want to see a curve movement of the ball when hit target. automatic calculate the distance and pick the power ball needs to hit target in curve movement.

    public Transform _Goal;    // target
    [Range(20f, 70f)] public float _angle;   // shooting angle
    public float taget_range;  // how far from me

    void Update()
    {
        taget_range = Vector3.Distance(gameObject.transform.position, _Goal.position);

        if (Input.GetKeyDown(KeyCode.Space) && taget_range <= 20f)
        {
            Launch();
        }
 
    }

    // Launches the cube to the target transform (_bullseye)
    private void Launch()
    {
        // source and target positions
        Vector3 pos = transform.position;
        Vector3 target = _Goal.position;

        // distance between target and source
        float dist = Vector3.Distance(pos, target);

        // rotate the object to face the target
        transform.LookAt(target);

        // calculate initival velocity required to land the cube on target using the formula (9)
        float Vi = Mathf.Sqrt(dist * -Physics.gravity.y / (Mathf.Sin(Mathf.Deg2Rad * _angle * 2)));
        float Vy, Vz;   // y,z components of the initial velocity

        Vy = Vi * Mathf.Sin(Mathf.Deg2Rad * _angle);
        Vz = Vi * Mathf.Cos(Mathf.Deg2Rad * _angle);

        // create the velocity vector in local space
        Vector3 localVelocity = new Vector3(0f, Vy, Vz);

        // transform it to global vector
        Vector3 globalVelocity = transform.TransformVector(localVelocity);

        // launch the cube by setting its initial velocity
        GetComponent<Rigidbody>().velocity = globalVelocity;

    }
2

I’ve just tried the code and it works fine. However, it hits the target position at the same height as itself. In other words, this formula assumes a flat terrain.

So I guess you are wanting to increase the initial velocity (on line 44) to still hit the target if it sits at an elevated position, is that your question?

3

I’ve been Googling and trying this out. Here is what I have come up with so far. It works on flat ground and when the target is raised higher.

public class Test : MonoBehaviour
{
    void Start()
    {
        m_body = GetComponent<Rigidbody>();
    }

    void Update()
    {
        if (    Input.GetKeyDown(KeyCode.Space)
            &&  Vector3.Distance(transform.position, m_goal.position) <= 20f )
        {
            Launch();
        }
    }

    private void Launch()
    {
        Vector3 pos = transform.position;
        Vector3 target = m_goal.position;

        // Split the distance into 2 components along the vertical 2D plane ...
        float deltaUp = pos.y - target.y;
        target.y = pos.y;
        float deltaAlong = Vector3.Distance(pos, target);

        // Calculate velocity based on 'turret' elevation
        var elevation = Mathf.Deg2Rad * m_angle;
        var numerator = m_halfGrav * ( deltaAlong * deltaAlong );
        var denominator = deltaUp + deltaAlong * Mathf.Tan(elevation);
        var vel = Mathf.Sqrt(numerator / denominator) / Mathf.Cos(elevation);

        if (vel <= 0f || float.IsNaN(vel) || float.IsInfinity(vel))
            return;

        // Calculate world angle
        var angle = Vector3.RotateTowards(
              (target - pos).normalized // Angle 'along the ground'.
            , Vector3.up
            , elevation                 // Angled up into the air.
            , 0f);

        // Fire ...
        m_body.velocity = angle * vel;
    }

#pragma warning disable 649
    [SerializeField] Transform m_goal;
    [SerializeField] [Range(20f, 70f)] float m_angle;   // 'Turret' angle.
#pragma warning restore 649

    const float m_halfGrav = 9.81f / 2f;
    Rigidbody m_body;
}
1 Like
4

Thank you so much Doug_B. you solved. :wink:

1 Like