CODEWITHSUNDEEP
c#unity-game-engine
user-44651
user-44651

Reputation: 4124

Multiple GameObjects Instantiated Between Two Angles

I am trying to spawn n GameObjects between angles equally spaced out.

Ideally, I'd like to be able to adjust the "cone" to so that the enemy can shoot in any direction, in any density.

Can someone see what I have done wrong?

enter image description here

These are enemy projectiles. That I am trying "scatter shot". Think of the dragon from Level 1 in NES Zelda:

enter image description here

Though, I am not entirely sure what is happening with my implementation.

enter image description here

Projectile.cs

    public Vector2 moveDirection = Vector2.zero;
    public float moveSpeed = 4.0f;

    private void FixedUpdate()
    {
        _body.MovePosition(transform.position + (new Vector3(moveDirection.x, moveDirection.y, 0).normalized) * (moveSpeed * Time.deltaTime));
    }

MultiShooter.cs 

public GameObject projectileObject;
public Transform projectileEmitter;
[Range(2, 10)] public int numToShoot = 3;
[Space]
[Range(0, 360)] public int angle = 30;
[Range(1, 50)]  public float rayRange = 10.0f;
[Range(0, 360)] public float coneDirection = 180;
public void OnStartShooting()
{
    for (int i = 1; i <= numToShoot; i++)
    {
        var projectile = Instantiate(projectileObject);
        projectile.transform.position = projectileEmitter.position;
        var projectileScript = projectile.GetComponent<Projectile>();
        projectileScript.moveDirection = DirFromAngle(((angle / i) + coneDirection)* pointDistance, rayRange);
        projectile.SetActive(true);
    }
}
public Vector3 DirFromAngle(float angleInDegrees, float range)
{
   return Quaternion.AngleAxis(angleInDegrees, Vector3.forward) * transform.up * range;
}

Editor script to show the lines.

private void OnSceneGUI()
    {
        MultiShooter fow = (MultiShooter)target;
        Handles.color = Color.magenta;

        Vector3 upDirection = fow.DirFromAngle((-fow.angle / 2.0f) + fow.coneDirection, fow.rayRange);
        Vector3 dwDirection = fow.DirFromAngle((fow.angle / 2.0f) + fow.coneDirection, fow.rayRange);

        Handles.DrawLine(fow.projectileEmitter.position, upDirection);
        Handles.DrawLine(fow.projectileEmitter.position, dwDirection);

    }

Upvotes: 1

Views: 44

Answers (1)

Ruzihm
Ruzihm

Reputation: 20269

For the ith object, the fraction of angular distance from one side of the range to the other can be expressed with the formula i/(numToShoot-1) for values ofnumToShoot > 1. If numToShoot == 1, you can just have the percentage be 50% to shoot right in the middle of the range.

Your drawing method seems to work with coneDirection ± angle/2, so we can subtract .5 from this angular percentage to express it in terms of angular distance from the center of the range.

Then we can use the same math as the drawing method with coneDirection + angle percentage * angle range:

public void OnStartShooting()
{
    for (int i = 0; i < numToShoot; i++)
    {
        var projectile = Instantiate(projectileObject);
        projectile.transform.position = projectileEmitter.position;
        var projectileScript = projectile.GetComponent<Projectile>();
        float anglePercentage;
        if (numToShoot == 1)
            anglePercentage = 0f;
        else
            anglePercentage = (float)i/(numToShoot-1f) - .5f;

        projectileScript.moveDirection = DirFromAngle(
                  coneDirection 
                + anglePercentage * angle, rayRange);
        projectile.SetActive(true);
    }
}

Upvotes: 1

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