Jittered cube positions on an order-4 Menger Sponge. Using Octane's built-ins for daylight and glossy material looks gorgeous.

Trying out a few of the LiveDB stock materials from OTOY.

Switched to specular material and set depths to 15 or so.

Using one cube model with rounded edges, and then instancing that one model using Octane's scatter node. I output the text for the scatter node using a Python program to reformat an OBJ export.

Stretched and rotated the single cube model before scatter-instancing.

Using the ID attribute in the scatter I could colorize each instance. I made a simple 10x10 pixel image using -- of all things -- Windows Paint. ;-)

I used a stock model of some factory pipes to add to the sponge, because... these were all for a 4k monitor screen saver, so I wanted some small objects to exercise that resolution on my 40" computer monitor.

Re-visiting the Houdini model that procedurally builds a Menger's Sponge. The nice thing is: I can fiddle with the spacing of the cubes, the model of the single cube that is instanced and other variations like jittering the positions. 

After tediously generating the entire model within Houdini, I decided to output the single cube and instance it using the 'scatter' node in Octane. I used the "id" attribute to allow coloring per-cube-instance.