How to stop the rotation of articles naturally

I created a fan in UE4,I want to control it from stationary to rotating, and then from rotating to stationary. I don’t know how to do it,I can let him start to rotate naturally, but not from rotation to stillness as in the real world.Please help me.Thanks

If I understand you correctly you do not want to toggle between stationary and rotating instantly but you want to start the rotation slowly and smoothly and do the same when turning the rotation off, correct?

If yes then you need to edit your curve in the Timeline node. You can manipulate the shape of the curve to not have any hard edges and create the smooth motion when state of the object is being changed.

Unrealistic jump from speed 0 to max speed.

Linear change. It starts at 0 and gets faster and faster in the linear fashion. Also unrealistic (but better than the first one).

281918-rotation-03.png

Smooth transition. Starts really slowly and then gets faster and faster logarithmically (usually it’s faster to change speed in car from 30km/h to 35km/h than from 0km/h to 5km/h).

Hello! I used the method you said,I simulated a slow acceleration and then a slow rest. and the effect is good.But I can’t control it。 I want a fan just like the real world。In other words, when I press F, the fan starts to rotate, and it will always rotate. When I press F or other buttons again, it will naturally stop rotating.Is there any way to do this? Thank you very much.

I also want to ask whether this slow and natural stop can only be achieved by timeline。Timeline how to achieve continuous rotation?

I did it. Although I thought it was a bit stupid, I broke it down into three parts.

When you enter your Timeline node there is a toggle box called “Loop”. When you turn it on your animation will keep repeating forever so you can use it for continuous rotation.

You can have animation for the smooth transition between 0 speed and max speed. You can use it when you press the F button (fan will slowly start to rotate). You can use the same timeline node but inverse pin to stop the fan smoothly (transition from max speed to 0 speed). You can create custom event which will be triggered by timer to keep rotating forever. You can also create second timeline node (with only max speed) which will be looped forever (loop checkbox inside Timeline node) which you can turn on and off by some other events. There are many ways of doing this.