Skip to main content
O
Overit-6
Participant
April 26, 2024
Answered

Expression help: Need comp to flip it's scale based on left/right movement

  • April 26, 2024
  • 2 replies
  • 486 views

I've got a composition of an animated bug. I have a script that gives it random movement left and right with pauses (so it'll crawl randomly left or right, stop, then crawl again at random intervals).

I'm looking for a way to flip the composition to face the direction it is moving and STAY that way while paused.

 

I'm currently using this hackey way to flip the X scale depending on the direction it's moving, but it always goes back to facing one way when it stops, when it should be facing the way it was facing when it stopped.

 

var movement = transform.position.velocity;
if (movement[0] < 0) {
	transform.scale
} else {
	[transform.scale[0]*-1,transform.scale[1]]
}

I hope that makes sense?

 

Any help would be awesome, thanks!

This topic has been closed for replies.
Correct answer Dan Ebberts

Try this:

var movement = transform.position.velocity;
if (Math.abs(movement[0]) < .01){
  t = time - thisComp.frameDuration;
  while (t >= 0){
    if (Math.abs(position.velocityAtTime(t)[0]) < .01){
      t -= thisComp.frameDuration;
      continue;
    }
    if (position.velocityAtTime(t)[0] < 0){
      transform.scale;
    }else{
      [-scale[0],scale[1]];
    }
    break;
  }
} else if (movement[0] < 0) {
  transform.scale;
} else {
  [-scale[0],scale[1]];
}

2 replies

Dan Ebberts
Community Expert
Dan EbbertsCommunity ExpertCorrect answer
Community Expert
April 26, 2024

Try this:

var movement = transform.position.velocity;
if (Math.abs(movement[0]) < .01){
  t = time - thisComp.frameDuration;
  while (t >= 0){
    if (Math.abs(position.velocityAtTime(t)[0]) < .01){
      t -= thisComp.frameDuration;
      continue;
    }
    if (position.velocityAtTime(t)[0] < 0){
      transform.scale;
    }else{
      [-scale[0],scale[1]];
    }
    break;
  }
} else if (movement[0] < 0) {
  transform.scale;
} else {
  [-scale[0],scale[1]];
}
    O
    Overit-6Author
    Participant
    April 26, 2024

    Perfect! That works great, exactly what I needed. Thank you (again!) Dan Ebberts

    Dan Ebberts
    Community Expert
    Dan EbbertsCommunity Expert
    Community Expert
    April 26, 2024

    That's great. It turns out that expression will break under certain conditions, so this one is probably better:

    var movement = transform.position.velocity;
val = value;
if (Math.abs(movement[0]) < .01){
  t = time - thisComp.frameDuration;
  while (t >= 0){
    if (Math.abs(position.velocityAtTime(t)[0]) < .01){
      t -= thisComp.frameDuration;
      continue;
    }
    if (position.velocityAtTime(t)[0] > 0){
      val = [-scale[0],scale[1]];
    }
    break;
  }
} else if (movement[0] > 0) {
  val = [-scale[0],scale[1]];
}
val
    Mylenium
    Mylenium
    Legend
    April 26, 2024

    You need to run it in a loop and check every frame.

     

    Mylenium

    Firefly Community Gallery
    Adobe Firefly

    Remix with Firefly Community Gallery

    Thousands of free creations to fall in love with and remix in Firefly.

    Explore now
    Terms & ConditionsAccessibility statement
    Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices