How can I put some edit mode funtions into the game

for example, I want to use spline in my game, the functions can be same as in the edit mode

I’m afraid you have to write them as part of your game. There’s no box in blueprints you can tick which says, make this editor mode utility work in game play.

It’s not too bad though, as you only have to give the player a widget, and when they move the widget, you use a blueprint to move part of your spline.

thanks a lot !