static protected Vector3 GetCenter (GameObject go)
{
UIWidget w = go.GetComponent<UIWidget>();
UICamera cam = UICamera.FindCameraForLayer(go.layer);
Vector3 center = go.transform.position;
if (w != null)
{
Vector3[] corners = w.worldCorners;
center = (corners[0] + corners[2]) * 0.5f;
}
center = cam.cachedCamera.WorldToScreenPoint( center );
center.z = 0;
return center;
}