3D Spiderweb (fast, 28 sec)

Pure blue:  depth 1
The "yellower" -- the greater the depth.

In 3D, it takes four spheres to generate an Apollonian sphere packing.  After scaling of the quartet so that the greatest curvature is 1, there are still three parameters: x, y, z.  In the animation  above, x and y are the standard coordinates, and z is turned into time   (z = 0..1).

Click on the animation to get a bigger size.

Sofware used:  Processing.js  and  ImageJ (fiji)