hi!

here's a realtime shader editor (as world machine is for terrain):
http://www.darksim.com/html/dt25_description.html

some screens of the prog:
http://www.darksim.com/html/body_dt25_screen_shots.html

here are some screens with these shaders:
http://www.darksim.com/dgallery/darktree_gallery.html

mfg, joey.