2Amatsu: http://unity3d.com/support/resources...ilt-in-shaders
2SaM_ времени проверять нет, так что
public Rigidbody drop;
Update() {
if (Input.GetKeyDown("g")) {
var rb = Instantiate(drop, transform.position + transform.forward, Quaternion.identity) as Rigidbody;
rb.AddForce(transform.forward * 1000, ForceMode.Impulse);