Animating shapes vs masks in After Effects

Question

Can anyone tell me how I'm going to get the best performance out of AE - I have a number of circles I need to animate expanding which are essentially stroked lines. Just made some paths with very thick strokes and it seems to be chugging a bit. I'm wondering if I would be better off with a Solid, with a circular mask on it, if that's faster to render - more over, I'm looking for a document that explains how Shape layers are rendered vs Masks.

Is there any reading anywhere on performance for this kind of thing? Have any of you come across this?

Edit

I'm running a iMac, 27-inch, Mid 2011

Processor 3.4 GHz Intel Core i7

Memory 8 GB 1333 MHz DDR3

Graphics AMD Radeon HD 6970M 2048 MB

Software Mac OS X Lion 10.7.5 (11G63b)

Answer 1

Rendering a series of expanding circles (say less that 20) should not be a particularly slow task.

Check this page about how to improve performance in AE. http://helpx.adobe.com/after-effects/using/improve-performance.html

AE doesn't render the same way as non-linear editors like Final Cut or Premiere, so rendering can take longer (but users are usually working on shorter sequences than in FCP).

When you are preparing your work, try to work at lower quality settings, ie at 25% zoom, or quarter resolution, only zooming to 100% to check specific frames - get the motion working correctly at a lower res - this will save you a lot of time.

I don't think animating paths rather than masks will make a particular difference to the speed.

Answer 2

The performance should not take the decision for you which tool you are better off with in your case, since there won't be a huge difference, as tomh has stated correctly.

Rather let the style / type of animation be a reason for a specific tool. For example, an adjustment layer or a solid with an animated mask to which you apply a stroke effect gives you nice possibilities if you want to animate the line appearing on the screen as if it was drawed. However, with shape layers you can use a repeater or other path operations to create nice algorithmic animations.

AE's performance when rendering shapes is less significant here than your performance when playing around with options. When your animation of multiple circles can be done quickly with a shape and a repeater, you'd better not use masks.