Auto-orient along path doesn’t work when there’s a Position expression

[Dan Ebberts]

Just curious–what’s the expression?

Dan

[Noel Powell]

The short answer is it’s a wiggle expression. It’s actually a wiggle expression within an if/else statement. The layer is 3D and the expression makes the layer wiggle in three dimensions as it moves along the path, which also twists and turns in three dimension. And even when the layer wiggles off the path, it still stays oriented to the next keyframe, which I like.
However, as soon as it reaches the last keyframe, it stops orienting. I’ve done simplified tests with the same results. I made the layer 2d, and tried just animating it to move across the screen, with just 2 keyframes. It still goes back to its original orientation at the end of the animation.

After Effects Templates – digital glitch effects, 80s VHS effects, old film effects, art effects, and more: https://CreationEffects.com

[Noel Powell]

The short answer is it’s a wiggle expression. It’s actually a wiggle expression within an if/else statement. The layer is 3D and the expression makes the layer wiggle in three dimensions as it moves along the path, which also twists and turns in three dimension. And even when the layer wiggles off the path, it still stays oriented to the next keyframe, which I like.
However, as soon as it reaches the last keyframe, it stops orienting. I’ve done simplified tests with the same results. I made the layer 2d, and tried just animating it to move across the screen, with just 2 keyframes. It still goes back to its original orientation at the end of the animation. It seems to do this no matter what I change the expression to. And if I take the expression out completely, it works fine.

After Effects Templates – digital glitch effects, 80s VHS effects, old film effects, art effects, and more: https://CreationEffects.com

[Dan Ebberts]

It might be very helpful to see the exact expression.

Dan

[Noel Powell]

…Sorry for the double post.

And sure, here’s the expression:

if (effect(“Turn on Automatic Wing Flapping”)(“Checkbox”)==1)
{ wiggle(effect(“Position Wiggle Speed (times per sec)”)(“Slider”),effect(“Position Wiggle Amount (in pixels)”)(“Slider”)) }
else
{ value }

After Effects Templates – digital glitch effects, 80s VHS effects, old film effects, art effects, and more: https://CreationEffects.com

[Dan Ebberts]

That’s interesting. One thing you could try is turning off Auto-Orient and instead using an orientation expression like this:


t = position.key(position.numKeys).time;
if (time < t)
lookAt(position,position + normalize(position.velocity))
else
lookAt(position,position + normalize(position.velocityAtTime(t-.001)))


Dan

[Noel Powell]

Dan, that seems to work perfectly. Thank you so much.

I’m curious, did you run any tests and see what I was talking about? I’m considering reporting the bug.

After Effects Templates – digital glitch effects, 80s VHS effects, old film effects, art effects, and more: https://CreationEffects.com

[Dan Ebberts]

>did you run any tests

I did. It looks like it could be a bug. I’d say go ahead an report it.

Dan

[Tolga Sayan]

Hi Kevin, Hi Dan..

I really need your help..I am a new in scripts and I have spend minimum 12 hours undertsanding this very useful script that Kevin I guess has written… I have found it in VC forum…

I need help in Auto orienting the car when car’s Y axis changes..

Here is the AEP file,

https://www.dropbox.com/s/dmqygnye8fctnja/MaxWheel_Car.aep?dl=0

Best,

Tolga / Turkey

[Matthias Stoll]

Hi Dan, hi everybody,

I just found out about the pointOnPath expression. It gives you any point on a path based on a percentage value. Of course, this is very powerful because you can change or even animate the motion path while your objects keep aligned to it. (In my opinion pasting path information onto an objects position is not helpful when you need to align many objects or be able to do quick adjustments. And animate the motion path is impossible)

“auto-orient” does work, but as soon there is no animation it snaps to a seemingly random orientation. (before and after the animation)

In this example I use a slider as input to animate the percentage value. But this is not related, whenever there is no movement on the layer, it snaps. I would simply like to copy the first and last “auto-orient” values when there is no animation. Is it possible to replace “auto-orient” with an expression which does the trick?

L=thisComp.layer(“Shape Layer 1”);
p=L.content(“Rectangle 1”).content(“Path 1”).path;
p.pointOnPath(effect(“Slider Control”)(1),time)+L.position

Help would be much appreciated, I have tons of ideas how I could make use of this.