src/Neuron/GameServer/Map/Movement.php
public function setUp (Neuron_GameServer_Map_Vector3 $start, Neuron_GameServer_Map_Vector3 $end)
	{
		$this->startUp = $start->normalize ();
		$this->endUp = $end->normalize ();
	}
public function setUp (Neuron_GameServer_Map_Vector3 $start, Neuron_GameServer_Map_Vector3 $end)
	{
		$this->startUp = $start->normalize ();
		$this->endUp = $end->normalize ();
	}
Set "UP" vector that will be interpolated