unity3d 拖動物體代碼

var mouseOverColor = Color.blue;
private var originalColor : Color;
function Start () {
 originalColor = renderer.sharedMaterial.color;
}
function OnMouseEnter () {
 renderer.material.color = mouseOverColor;
}
function OnMouseExit () {
 renderer.material.color = originalColor;
}
function OnMouseDown () {
 var screenSpace = Camera.main.WorldToScreenPoint(transform.position);
 var offset = transform.position - Camera.main.ScreenToWorldPoint(Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z));
 while (Input.GetMouseButton(0))
 {
  var curScreenSpace = Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z);
  var curPosition = Camera.main.ScreenToWorldPoint(curScreenSpace) + offset;
  transform.position = curPosition;
  yield;
 }
}