3d Noise in Alpha Channel

[Brian Sneed]

I am trying to produce something similar to the images seen
here: https://jeremyw.com/C4D_Stuff/3dnoise1.html

I have been able to achieve similar results, but the
varying sizes of spheres appear as thin “skins” with
no volume. The individual steps in the images above
appear to have some volume – or extruded properties.

Just wondering if anyone can give me some insight on
how I might be able to get similar results.