I’ve already made a UMG menu by Button and TextBlock, .etc. Now I want to make a menu in the VR game, and can I directly transplant the former into the VR environment, and when the raycast emitted by a motion controller hits a button and then I pull the trigger, the button will act just as the mouse clicks it?
You need to create a 3D widget and put your UMG in it.
Here is a tutorial on how to do it:
https://docs.unrealengine.com/latest/INT/Engine/UMG/HowTo/Create3DWidgets/
Enjoy