///<summary>單選取物件</summary>
void SelectObj(RaycastHit hit)
{
SelectClear();
ISelectable item = hit.transform.GetComponent <ISelectable>();
if (item != null && item.Selectable)
{
if (!SelectingObjs.Exists(e => e == item))
{
SelectingObjs.Add(item);
item.BeingChosen();
Debug.Log("單選 " + item.Transform.name + " 共 " + SelectingObjs.Count);
}
}
}