Classic 3D: Can AfterEffects detect when an object appears halfway turned?

[brandonb96942845]

Hi all,

Got a question. I'm trying to automate something in AfterEffects that I have to do by hand. Short version is, when using Classic 3D, I'm trying to flip a series of cards over by rotating them 180 degrees around the Y axis. Doing it this way, I have to manually end one layer and start the next one to mimic one side of the card disappearing and the other one appearing.

If it weren't for the perspective shift between them, I could just do an if/else statement based on the number of degrees, and tell it that if the rotation was less than 90 degrees, one side would be visible and the other wouldn't, and vice versa.

The perspective shift adds an interesting wrinkle though, in that not all of the cards appear rotated 90 degrees from the camera's perspective at the same point. (For instance, the first one passes that point somewhere around -107.6 degrees, and so on)

My question is, is there a way to get AE to figure out when each card is turned 90 degrees not from its starting position, but from the camera's perspective?

[Mylenium · Accepted solution]

http://www.motionscript.com/design-guide/invisible-facing-away.html

Mylenium

[brandonb96942845]

That does the trick! Thanks Mylenium!