VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Mon Nov 29 2004 - 00:31:16 CST

Hi,
  The older versions of VMD had a very simple-minded way of coping
with the lack of color-per-vertex shading with POV-Ray and previous
versions of Tachyon. The new VMD 1.8.3 test versions have a completely
different way of exporting geometry which are much better at preserving
exact colors than previous versions were. The representations that
got the largest improvement as a result of the new code are Surf, MSMS,
and NewRibbons. The other representations should be exported nicely
even in the older versions of VMD. If you're having trouble making
this work well, let me know and I'll be glad to provide further suggestions.

  John Stone
  vmd_at_ks.uiuc.edu

On Wed, Nov 24, 2004 at 04:35:55PM -0600, Luis Rosales wrote:
>
> Hi Tatyana!
>
> Maybe it´s a problem of your gamma value??? (i.e. the overall colors are
> lighter than those of the vmd graphics window )
>
> In POV 3.6, you set the gamma value with:
>
> global_settings { assumed_gamma 1.0 } // ithink that 1.0 is the
> default value
>
> Maybe you can play with the midpoint/offset of your gradient to get your
> desired color gradient...
> Hope this helps,
>
> Luis
>
>
> > -----Mensaje original-----
> > De: owner-vmd-l_at_ks.uiuc.edu [mailto:owner-vmd-l_at_ks.uiuc.edu]
> > En nombre de Tatyana I. Igumenova
> > Enviado el: Miércoles, 24 de Noviembre de 2004 11:29
> > Para: vmd-l_at_ks.uiuc.edu
> > Asunto: vmd-l: Povray & color gradients
> >
> > Hi,
> >
> > Using vmd, I have colored methyl groups in my protein with BWR
> > color gradient according to the values of NMR order parameters.
> > When I used povray to generate a high-quality image, *some* of the
> > gradient colors were not correctly represented in the final .bmp file,
> > e.g. light pink methyls turned white etc. I got the same result when I
> > used Tachyon.
> >
> > Are there any changes that I have to make in the scene files
> > to faithfully
> > represent the color gradients that I see in my vmd image?
> >
> > Thanks very much,
> > Tatyana
> >
> >
> > --
> > Tatyana Igumenova, PhD.
> > Department of Biochemistry and Biophysics
> > University of Pennsylvania
> > 423 Guardian Drive
> > Blockley Hall, Room G-6
> > Philadelphia, PA 19104
> > Tel: 215-573-5969
> >
> >
>
>
> 

-- 
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