Fire Projectile In Ballistic Motion

Question

I am using the following to calculate velocity: https://gamedev.stackexchange.com/a/114547/39518

private void CalculateVelocity()
{
    Vector3 toTarget = Target.position - StartingPoint.position;

    // Set up the terms we need to solve the quadratic equations.
    float gSquared = Physics.gravity.sqrMagnitude;
    float b = Speed * Speed + Vector3.Dot(toTarget, Physics.gravity);
    float discriminant = b * b - gSquared * toTarget.sqrMagnitude;

    // Check whether the target is reachable at max speed or less.
    if (discriminant < 0)
    {
        // Target is too far away to hit at this speed.
        // Abort, or fire at max speed in its general direction?
    }

    float discRoot = Mathf.Sqrt(discriminant);

    // Highest shot with the given max speed:
    float T = Mathf.Sqrt((b + discRoot) * 2f / gSquared);

    // Convert from time-to-hit to a launch velocity:
    Velocity = toTarget / T - Physics.gravity * T / 2f;
}

I'd now like to take the calculated velocity and move the projectile using the following: https://gamedev.stackexchange.com/a/119636/39518

I came up with the following: "T" & "Velocity" are variables calculated in the first method.

private IEnumerator MoveProjectileToTarget()
{
   
    while(Projectile.position != Target.position)
    {
        // Standard ballistic motion:
        Vector3 point = StartingPoint.position
                      + T * Velocity
                      + 0.5f * T * T * (Vector3)(Physics.gravity);

        Projectile.position = point;

        yield return null;
    }
        
}

The current problem I have is the projectile is warping to it's target. I believe the issue lies in the while loop I created. Any help would be greatly appreciated. Thanks!

Answer 1

You're currently calculating just the position at the END of the arc (time T is the total time it takes to finish the whole flight). Did you mean to gradually step a t value from 0 up to T?

private IEnumerator MoveProjectileToTarget()
{
    for (float t = 0; t < T; t += Time.deltaTime) {
        Projectile.position = StartingPoint.position
                            + t * Velocity
                            + 0.5f * t * t * Physics.gravity;

        yield return null;
    }        
}