[plt-scheme] balls and sticks scripting

hi

Anyone knows how to do balls and sticks scripting in plt?
I need nothing fancy or animation.
I just need to automate importing points (balls) and lines (sticks)
from flat text file.
Appearance is not important, simple coloring is enough.
(I don't really need spheres or balls, so long as points and lines can
be distinguished)
Simple lighting variance, with distance to camera is enough.

Thanks