Menger Sponges (Blender)
Menger Sponges:
MathWorld:
http://mathworld.wolfram.com/MengerSponge.html
Wikipedia:
https://en.wikipedia.org/wiki/Menger_sponge
Here on Instructables there's this:
https://www.instructables.com/id/Lego-Menger-Sponge...
On Thingiverse there's this:
Customizer:
http://www.thingiverse.com/thing:240739
and these:
http://www.thingiverse.com/search?cx=0155257477281...
On Youtube there's this:
https://www.youtube.com/results?search_query=Menge...
and now, for the record, there's Blender:
http://www.blender.org/
Adding a Sponge
Shift-A
Mesh / Extras / Menger Sponge
Pick Your Level
Starting with level 1 (usually 3 is about the highest MOST PCs / Laptops / and Printers will support).
Adjust the width.
That's it.
Enjoy.