u3射线

Ray ray2 = Camera.main.ScreenPointToRay(Input.mousePosition);  
            //RaycastHit  是一个结构体对象，返回储存的碰撞信息  
            RaycastHit hitInfo = new RaycastHit();  
            if( Physics.Raycast(ray2,out hitInfo)){  
                if (hitInfo.collider.gameObject.name == "Cube"){  
                    Debug.Log("hit_point = "+hitInfo.point);  
                }  
            }