How to compensate for additional velocity

Question

Right now I am working on a simple tank AI - it drives through the level and shoots at any enemy objects in range. There's no physics involved except for a constant velocity added to missile's velocity to account for tank's velocity - the code looks like this:

private void Update()
{
    if (Time.time - _lastMissileTime < _missileCooldown)
    {
        return;
    }

    Enemy target = GetClosestEnemy();

    if (target == null)
    {
        return;
    }

    Vector3 shootDirection = target.transform.position - transform.position;

    Shoot(shootDirection);

    _shotTargets.Add(target);

    _lastMissileTime = Time.time;
    
    _targets.Clear();
}

private Enemy GetClosestEnemy()
{
    foreach (Enemy enemy in _enemies)
    {
        if (_shotTargets.Contains(enemy))
        {
            continue;
        }
        
        if (Vector3.Distance(transform.position, enemy.transform.position) > _missileRange)
        {
            continue;
        }

        _targets.Add(enemy);
    }

    if (_targets.Count < 1)
    {
        return null;
    }
    
    _targets.Sort((x, y) => Vector3.Distance(x.transform.position, transform.position).CompareTo(Vector3.Distance(y.transform.position, transform.position)));

    return _targets[0];
}

private void Shoot(Vector3 direction)
{
    direction.Normalize();
    
    Missile missile = Instantiate(_missilePrefab, transform.position, Quaternion.LookRotation(direction));

    Vector3 tankVelocity = _mover.Direction * _mover.Speed;
    Vector3 missileVelocity = direction * _missileSpeed + tankVelocity;

    missile.Initialize(missileVelocity, _missileLifetime);
}

Here's how it looks like in debug view - yellow lines are for the direct trajectory to target, red lines show the actual trajectory of a missile.

https://gfycat.com/lavishcautiousgrayfox

Now I want to add different levels of experience to my tank AI so veteran level tanks will hit more often - while I could simply remove the tanks velocity from missile velocity calculation for veteran tanks it kinda feels hacky. I would like to determine what direction the tank has to shoot at to compensate for additional velocity but I simply can't figure it out. I tried simulating the actual shot direction and offseting the direct direction to the target by it but it doesn't work most of the times. I would love any help and ideas!

How to compensate for additional velocity

0 Answers