Hi Mike,
I expressed myself poorly -- with real 3D I mean generated by f(x,y,z) and not the usual f(x,y, g(x,y) ) which are based on 2D with an extra function giving it a z value. I also meant the analytic onces - surely Koch, Klein etc... patterns can be perfectly (?) generated in 3D.
Rephrasing it correctly : using quaternions as a base and analytic functions - the most attractive ones are where j=k=0 (the 2D things) , the onces with k=0 can be found on the web :
http://www.bing.com/images/search?q=quaternion+fractals&FORM=HDRSC2 (beware , some are based on quads, but with some extra functions involved - not what I had in mind)
k != 0 may be more interesting, these are moving pictures
I hope I am wrong about these analytic 3D fractals, I profoundly hope .. i think Steel Bank CL has a quadlisp package-- not sure it is public (probably used on these futuresque computers OS's - but both NASA and Google already running one)
best Rob -- my excuses, indeed 3D gives a better experience than 2D - but I was thinking about the mathematics -- but as said when I define a direction between two points in 3D I can setup a certain thickness around this axis , and we have yet another kind of 3D , but still based on 2D.