From: John Stone (
Date: Wed Jun 10 2009 - 10:57:58 CDT


On Wed, Jun 10, 2009 at 05:29:08PM +0200, Bjoern Olausson wrote:
> Okay, I didn't look in that menu, stupid me... Thanks for that hint!

No problem. There are a lot of menus, so nobody can blame you if you
haven't seen them all yet :-)

> Before requesting another feature that might already exist:
> Is there a way to control the light intensity of every single light source?
> (I know i can edit them in the povray/tachyon file, but is it possible in
> VMD?)

Not currently. The rendering code in VMD can actually do this,
but it is (presently) always given full intensity white light colors
(1.0, 1.0, 1.0). This is something I could likely add in the next version
of VMD without much difficulty. With features like this, far more work
goes into adding new GUI controls and text commands than into writing
the low level code that does the rendering.

Another feature I hope to add in the next version of VMD is support
for user-defined lights that can have more sophisticated functionality,
such as distance-based attenuation, spotlights, etc. With that, users
can write scripts that have lights follow an atom selection, or shine
on a particular region of interest, etc. This can be done now using
Tachyon and a little Tcl script I've written if you'd like to play
with this sort of thing.

  John Stone

NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email:                 Phone: 217-244-3349
  WWW:      Fax: 217-244-6078