loopOut pingpong doesn’t work on a mask shape?

[Dan Ebberts]

I’m surprised it doesn’t work. Well, you can “roll your own” ping pong expression. This should work:


if (numKeys >1 && time > key(numKeys).time){
t1 = key(1).time;
t2 = key(numKeys).time;
span = t2 - t1;
delta = time - t2;
seg = Math.floor(delta/span);
t = delta%span;
valueAtTime((seg%2) ? (t1 + t) : (t2 - t));
}else
value


Dan

[Naveen Mallikarjuna]

Yeah, I’m surprised too. Here’s what I get:

Bad method arguments: loop is not supported for custom properties
Expression disabled.

I guess the animation of the mask shape is something loop doesn’t handle.

Naveen

[Navarro Parker]

How would do you a normal (non ping-pong) loop for masks?

[Dan Ebberts]

This should work:


if (numKeys >1 && time > key(numKeys).time){
t1 = key(1).time;
t2 = key(numKeys).time;
span = t2 - t1;
delta = time - t2;
t = delta%span;
valueAtTime(t1 + t)
}else
value


Dan

[Navarro Parker]

Thanks Dan! Works like a charm!

(And Happy New Years Eve!)

[Ed Stables]

Thank you so much for coming up with this expression. Much appreciated

[Luis Merino]

Hello,
I have a big question!

I’m trying to loop a path but i want the loop to be “Pingpong” after the first keyframe.
According to what I’ve read, this is the expression for looping paths but it only works for cycle loop.

Is there any way to make it work as a pingpong loop?

if (numKeys >1 && time > key(numKeys).time){
t1 = key(1).time;
t2 = key(numKeys).time;
span = t2 - t1;
delta = time - t2;
t = delta%span;
valueAtTime(t1 + t)
}else
value

[Dan Ebberts]

Try it this way:


if (numKeys > 1 && time > key(numKeys).time){
t1 = key(1).time;
t2 = key(numKeys).time;
span = t2 - t1;
delta = time - t2;
seg = Math.floor(delta/span);
t = delta%span;
valueAtTime((seg%2) ? (t1 + t) : (t2 - t));
}else
value


Dan

[Tim Gala]

This is awesome Dan.
However, in my case, it seems to result in some flashing.
I rendered to see if it was just a preview performance thing.
Take a look if you have a moment to look at a simple wavy line.
Wavy Line example