Flipside expression error

[Dan Ebberts]

I don’t think I’ve ever seen that error before. Does the error only happen at certain rotations, or do you always get it as soon as you enable the expression? Any way you can post or send the project?

Dan

[Andy George]

Hi Dan,

Thanks for your time.

There is only 1/2 rotation on the null. Basically just flipping a layer to reveal another layer behind it.

The expression seems to work if I enable it while the current time indicator is
a few seconds into the comp.
Once I move the time indicator to the start of the timeline, I get the error.

Here is an AEP-

https://www.chiselindustries.com/Client/lottery.zip

Thanks

-Andy

[Dan Ebberts]

Ah, OK. When the scale of the layer is zero, the toCompVec() operation doesn’t have anything to work with. Try this variation to defend against that condition:

if ((Math.abs(scale[0]) > .001) &&( toCompVec([0, 0, 1])[2] > 0 )) value else 0

Dan

[Andy George]

Works like a charm!

Thanks again

-Andy

[Eliezer Cisner]

And how to I apply this fix to a nested comp (camera’s in parent comp)?

My current expression:

parentComp = comp("Parent Comp");
parentLayer = parentComp.layer(thisComp.name);
if(parentLayer.toWorldVec(toWorldVec([0,0,1]))[2] > 0) value else 0

[Kevin Barnum]

This didn’t work for me in CC. Turns out AE doesn’t like such a small value for the scale check condition. Changed it to the following and I no longer get expression errors.

if ((Math.abs(scale[0]) > 0.01)&&( toCompVec([0, 0, 1])[2] > 0 )) value else 0

[Teague Chrystie]

Just in case anyone else stumbles across this error and finds this page among the lonesome handful of Google results, I was experiencing this issue as well, and while protecting the Scale from low values seemed to work alright sometimes, ultimately my issue was solved by making sure that there’s never a point in the comp where my error-prone layer wasn’t active. In other words, the layer that had my expression on it was shorter than the actual comp, and when the layer ceased to “exist” the expression got mad. Making that layer longer than the comp seems to resolve it.

Good luck, folks.