Hi,
i'm playing with the plot method and i don't understand what's the
meaning of the 3d layout algorithms (like fr3d and kk3d). Can i plot
on a PNG?
No, you can't, the plotting methods expect a 2D layout. I wrote a 3D
graph visualiser some time ago in Python using igraph and OpenGL and
these methods were handy to calculate a nice layout, but otherwise
they're quite useless without an external visualisation engine.
However,
since the functions are there in the core C library and it cost me
nothing to implement the interface in Python, I did it.
If you are interested, I can try and dig up the code for that old 3D
visualiser of mine and send it to you. It's more like pure eye candy
as
it cannot really cope with larger graphs (i.e., more than a couple of
hundred vertices), but you can rotate the graphs around or put it in
auto-rotating mode.