private Camera cam;//发射射线的摄像机
private GameObject go;//射线碰撞的物体
private Vector3 screenSpace;
private Vector3 offset;
private bool isdrage = false;
void Start()
{
cam = Camera.main;
}
void Update()
{
if (isdrage == false)
{
//整体初始位置
Ray ray = cam.ScreenPointToRay(Input.mousePosition);
//从摄像机发出到点击坐标的射线
RaycastHit hitInfo;
if (Physics.Raycast(ray, out hitInfo))
{
//划出射线,只有在scene视图中才能看到
Debug.DrawLine(ray.origin, hitInfo.point, Color.red);
go = hitInfo.collider.gameObject;
screenSpace = cam.WorldToScreenPoint(go.transform.position);
offset = go.transform.position - cam.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z));
}
}
//拖拽物体不能为空
if (go != null)
{
//拖拽
if (Input.GetMouseButton(1))
{
Vector3 currentScreenSpace = new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenSpace.z);
Vector3 currentPosition = cam.ScreenToWorldPoint(currentScreenSpace) + offset;
go.transform.position = currentPosition;
isdrage = true;
}
else
{
//结束后,清空物体
go = null;
isdrage = false;
}
}
}