public void CheckpointTrigger(GameObject cp, MyRaceAgent agent)
{
int index = checkpoints.IndexOf(cp);
Vector3 nxtCheckpointPos = checkpoints[(index + 1) % NCheckpoints].transform.position;
agent.CheckpointTrigger(nxtCheckpointPos, index);
}
void OnTriggerEnter(Collider other)
{
// MyRaceAgent agent = other.gameObject.GetComponent<MyRaceAgent>();
MyRaceAgent agent = other.GetComponentInParent <MyRaceAgent>();
CheckpointManager manager = GetComponentInParent <CheckpointManager>();
manager.CheckpointTrigger(gameObject, agent);
}