3D Stroke Around objects

[Aaron Strader]

It’s technically, what you’d call 2 1/2 D. It doesn’t operate in AE in a true 3D space, so it’s up to you to make it look that way. The easiest way is to know when your stroke is roaming in it’s own 3D space. Incorporate it’s percieved Z depth in using multiple layers of the 3D stroke in with single layer you need masked.

Or, you can also wrap multiple layers of your object around the 3D stroke.

I had to demo this to a client who purchased it, and we took a pair of handcuffs, took a swirly 3D stroke that had some Z depth dips in it, and masked off the portions of the ‘cuffs where the stroke was “dipping” behind the object, while not masking where we wanted to make the curves arc over the front of the cuffs.

It was a really simple trick, and took 4 layers.

2 mask layers of the cuffs.
3D stroke
1 solid layer of the cuffs.

It was fairly simple from there.

-Aaron

https://www.stopfcc.com/
Knock it off! I like my radio and television the way it is…

[Steve Roberts]

Nothing is true 3D in AE, technically. The AE space is made up of flat layers, and any 3D effects applied to a layer reside on that flat layer, like a movie of a 3D object on a movie screen. As long as that flat layer is left as a 2D layer, it will always be facing us, and we see the 3D “movie” as if it were real. Syncing the effect’s camera with AE’s camera completes the illusion.

I believe it was Chris who accurately described 3D Stroke as a string of discs flat-on to camera. The discs are arranged in a path on a 2D layer. Yes, it is still an illusion on a flat plane, but with a twist: the effect has a means of cutting itself behind objects at a certain Z-position, giving the illusion of being in 3D space. It works pretty well with simple setups.

One way is to duplicate your 3D stroke layer, then reduce the effect’s Z clip back parameter (under “camera”) for the front layer until the object in the middle is revealed. You might need to solo each 3D stroke layer to understand what is going on.

I can’t see it working with multiple moving objects, though you can try using an expression to tie the Z clip value to the moving object’s Z position. You’d probably need a dupe of the 3D stroke layer between each object layer … could get tricky.

Maybe it’s another one of those situations that call for a real 3D app. 🙂

Steve