啊..敗給旅遊燃燒殆盡症候群了，昨天晚上不小心睡著，忘記設鬧鐘，再醒來就已經過12點了QwQ

解bug

UnassignedReferenceException: The variable panel of LineRendererSettings has not been assigned.
You probably need to assign the panel variable of the LineRendererSettings script in the inspector.
UnityEngine.GameObject.GetComponent[T] () (at /Users/bokken/buildslave/unity/build/Runtime/Export/Scripting/GameObject.bindings.cs:28)
LineRendererSettings.Start () (at Assets/LineRendererSettings.cs:30)

他說我沒有把panel變數賦值給LineRendererSettings.cs

這個是因為我在Day 25. VR菜單3，對這句話只理解了一半：

Left-click and drag the panel from your Hierarchy window into the slot on the LineRendererSettings script on your Capsule (Figure 21).

　
中文的傻瓜理解應該是：

1. Add LineRendererSettings script on your Capsule完後
2. 才是drag the panel from your Hierarchy window into the slot on the LineRendererSettings script on your Capsule

　
　
　
恩！這樣bug就沒了

Q:為什麼屬於UI的canvas要放在3D object的cube下？

參考：
https://ithelp.ithome.com.tw/articles/10280153
https://learn.unity.com/tutorial/creating-a-vr-menu-2019-2#6036dc27edbc2a50f848a701