VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Thu Jan 29 2004 - 20:21:53 CST

Charles,
  I could address your request in one of several ways.
I'll take a look and see what's causing the NewRibbons code to
generate fewer colors. A cursory examination didn't immediately
reveal the answer, but it should be easy to fix. In any case,
with the NewRibbons code I could add color interpolation
at each "section" which would end up with color gradients that
are smoother than even the old ribbons code. There are times when
you want a sharp color change and times when smooth is preferable,
so the interpolation solution isn't as good as tying the color more
closely to individual atoms along the ribbon. I'll look at this some
more and let you know when I have something you can try out. It should
be a minor change.

  John Stone
  vmd_at_ks.uiuc.edu

On Thu, Jan 29, 2004 at 06:40:15PM -0500, Charles_at_Schwieters.org wrote:
>
> Hi--
>
> I have noticed the following behavior in versions 1.8.1 and 1.8.2:
>
> there's an unfortunate feature of the new ribbons drawing method:
> while its shape is more visually appealing than the old ribbons
> method, it does not use as many colors in the ray tracing output, so
> that the discrete coloring is uglier.
>
> To see this:
> load a structure, and color by index, and use the ribbons and new
> ribbons drawing method - then render it using a ray tracer (I get the
> same results with povray and tachyon).
>
> % grep color trace.pov | sort | uniq | wc
> 58 344 2923
> % grep color newRibbons.pov | sort | uniq | wc
> 9 50 424
> % grep Color trace.dat | sort | uniq | wc
> 58 634 4305
> % grep Color newRibbons.dat | sort | uniq | wc
> 9 95 679
>
> One can see that the new ribbons versions contains fewer colors (9
> vs. 58). Would it be possible to change the newRibbons output code to
> use the larger number of colors?
>
> thanks--
> Charles
>
> --
> Charles Schwieters email: Charles.Schwieters_at_nih.gov
> www: http://schwieters.org/cds
> phone: (301) 402-4914 PGP key: http://schwieters.org/cds/pgp.txt 

-- 
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: johns_at_ks.uiuc.edu                 Phone: 217-244-3349              
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078