I wrote a little Matlab program to generate the targets:
And, yes, all you Matlab experts, I know it can be coded a lot more efficiently, even by me. I wrote it this way so that any Java or C programmer could figure it out.
Here’s what a close up of the first four layers looks like:
Here’s five layers:
And, finally, seven, which is what I’m going to start with because it makes it easier to focus: