"Play Animation Forward" & "Play Animation Backward" do not function properly

General Issues and Bug Reporting
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1

Summary

“Play Animation Forward” and “Play Animation Backward” do not actually do what the tooltips say they do for UMG widget animations. According to the description, the relative state of the animation should be used when playing the animation forward or backwards. This would mean that an animation that has finished will not play forward and, likewise, an animation at the beginning will not play reverse.

Currently, these both function as if “Play Animation” was just called with the play mode set to either Forward or Reverse. This should operate as a separate explicit play mode which does not take animation state into account.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

UI/Tools

Steps to Reproduce

  • Create an animation for an element where you change the opacity from 1 to 0 over 3 seconds.
  • Create a verse field float value and then use that float value called Test_Play_Val.
  • Setup a condition for Test_Play_Val <> 0 to “Play Animation Forward” for your created animation.
  • Setup another condition for Test_Play_Val = 0 to “Play Animation Reverse” for your created animation.
  • Add the widget to the player’s scren through Verse.
  • Set the Test_Play_Val to 1 and notice your animation begin to fade-out the element.
  • While that animation is playing, set Test_Play_Val to 0.

Expected Result

The expected result here would be for the animation to stop in its current state as it’s playing and then begin to play in the opposite direction from the its current state, thus creating a smooth transition in directionality for the element’s opacity.

Observed Result

You will notice that, rather than having a smooth fade-in over the elapsed duration from the animation’s current state, the opacity of the element will immediately drop to 0 before fading back into to 1 over 3 seconds.

Platform(s)

UEFN for PC

2

If the animation is finished it is considered completed and reset. Regardless of direction. Play Forward and Backward will just trigger from “” to “” where max is the start or the end.

That function is for when you want to switch states on the middle of the animation or if it is paused. Then they will start from the current frame and not always from the beginning/end (for that you must use the normal play animation function). They are not to avoid “replays” but instead to allow sudden direction changes on the track

3

I see. My assumption was that the animation’s state persisted while it in-fact does not. They key issue I was encountering was that I was effectively playing the reverse animation again without manually tracking if it was already in the target state. (Example: Instead of just saying play fade-out for item 1 anytime I view item 2 or 3, the logic should be play fade-out for item 1 if item 1 was being viewed AND anytime I view item 2 or 3)