Unity 拖动相机跟随鼠标（手指）移动（例如移动小地图）

• demo下载地址 demo下载地址
• 代码片段

	if (Input.GetMouseButtonDown(0))
	        {
	            Plane plane = new Plane(Vector3.up, Vector3.zero);
	            Ray ray = miniCamera.ScreenPointToRay(Input.mousePosition);
	            float distance;
	            if (plane.Raycast(ray, out distance))
	            {
	                dragStartPos = ray.GetPoint(distance);
	            }
	        }
	        if (Input.GetMouseButton(0))
	        {
	            Plane plane = new Plane(Vector3.up, Vector3.zero);
	            Ray ray = miniCamera.ScreenPointToRay(Input.mousePosition);
	            float distance;
	            if (plane.Raycast(ray, out distance))
	            {
	                //获取到这条射线到XZ平面上具体点的位子信息
	                dragCurrentPos = ray.GetPoint(distance);
	                Vector3 difference = dragStartPos - dragCurrentPos;
	                Debug.Log(difference);
	                newPos = miniCamera.transform.position + difference;
	            }
	            miniCamera.transform.position = Vector3.Lerp(miniCamera.transform.position, newPos, moveTime * Time.deltaTime);
	        }
	```