unity3d predict location of target
private Vector3 predictedPosition(Vector3 targetPosition, Vector3 shooterPosition, Vector3 targetVelocity, float projectileSpeed)
{
Vector3 displacement = targetPosition - shooterPosition;
float targetMoveAngle = Vector3.Angle(-displacement, targetVelocity) * Mathf.Deg2Rad;
//if the target is stopping or if it is impossible for the projectile to catch up with the target (Sine Formula)
if (targetVelocity.magnitude == 0 || targetVelocity.magnitude > projectileSpeed && Mathf.Sin(targetMoveAngle) / projectileSpeed > Mathf.Cos(targetMoveAngle) / targetVelocity.magnitude) {
Debug.Log("Position prediction is not feasible.");
return targetPosition;
}
//also Sine Formula
float shootAngle = Mathf.Asin(Mathf.Sin(targetMoveAngle) * targetVelocity.magnitude / projectileSpeed);
return targetPosition + targetVelocity * displacement.magnitude / Mathf.Sin(Mathf.PI - targetMoveAngle - shootAngle) * Mathf.Sin(shootAngle) / targetVelocity.magnitude;
}