VMD-L Mailing List

From: Vieri Di Paola (dipaola_at_cli.di.unipi.it)
Date: Wed Mar 01 2000 - 03:59:15 CST

Hello vmd-list,

I am a Biology student and wish to make a simple program for viewing pdb
molecules. I know VMD is the best :-) but, as a small project, I would
like some information on the following matter. My project consists in
drawing spheres for each atom. My problem is that I cannot find any help
anywhere on the Internet that explains an algorithm for efficient >15000
spheres drawing. I suppose "hidden" spheres (according to a
certain view angle) shouldn't be drawn, etc... VMD probably uses an
efficient algorithm for the "spatial" model representation but I realize
that the source code is quite "loaded" with features that I'm not looking
for. Can anybody tell me exactly where to look at in the VMD source code?
Or can anybody tell me where (if) I can find a simple, to-the-point
tutorial that handles this rendering problem?

My project can be summarized as follows:

1- take a set of x,y,z atom coordinates from a pdb file (simple)
2- apply algorithm to "sort out" the atoms I need to draw according to the
user's viewing angle
3- draw only the "visible" atoms by plotting spheres with the appropriate
Wan Der Waals radius
4- update "visible" and "hidden" atoms when user rotates molecule

I'm using FLTK (www.fltk.org) and MESA (www.mesa3d.org) on Linux.

Thanks in advance,

Vieri Di Paola