Concentric animation using masking?

I have a display object like this 

ABasAlq.png

I want to animate this the following way using some sort of mask. 

bmF32Fq.gif

Is it possible with masks? 

If I have to use sprites, I will have to use a lot of frames for a smooth transition, hence the mask.

The circles will be regular. 
This is just a sample. 

Is there any fool-proof way to achieve this. Like using a circular mask or something?

Nope. The closest workaround is splitting up your image into 180 degree arcs and using a mask on each of these. Even this, you will find, is a tedious process - had to do this myself.

The circles will be regular. 
This is just a sample. 

Is there any fool-proof way to achieve this. Like using a circular mask or something?

Nope. The closest workaround is splitting up your image into 180 degree arcs and using a mask on each of these. Even this, you will find, is a tedious process - had to do this myself.