it is really easy, i was surprised to see how much easy...
just look for M3D (as example here
http://the-aposhack.deviantart.com/gallery/28953017 )
till you found scenery you really like and think that the program is a door to there:
then is just simple as copy,paste and click a button:
1)copy the parameter you see in the image comment
2 )click the..."paste txt parameter bottom "
3)and then the " calcolate 3D"
Done that you may switch more lights on, change "lens" to enlarge or restrict the Field Of View , change position.
Basically to start you should be able to copy & paste, and click a button , that open the door
then come natural learn how to move inside and little by little even how modify at a deeper level,
zoom in/out, rotate, switch lights on/off , and change FOV and colors allow already you to radically modify the scenanery you started with
And the coolest thing of M3D, is that so many like share their parameters (not to be cloned by to be tweaked and the best way to thank for this is always remember to give the credit and a link back to the original..or the nice game will end )
and that allow you a direct entry in the 3d fractal world