VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Wed Apr 06 2011 - 09:55:32 CDT

Hi,
  Nothing has changed with how VMD 1.9 renders scenes to POV-Ray, but
one thing that is different now is that when VMD starts up, the
depth cueing feature is enabled by default. You can turn off depth cueing,
and then you should get images that look the way you expect them to. The
reason that you get a black background with depth cueing enabled is that
the "fog" effect is causing all of the pixels to be assigned to the fog
color (the background color in the case of VMD) because they are at
"infinite" distance, so they are fully saturated. If you disable depth
cueing, then any pixel that doesn't show molecular geometry should be
entirely transparent, and the alpha values should be set as you expect for
transparent objects in the scene...

Let me know if you have further questions about this.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Tue, Apr 05, 2011 at 11:22:21PM -0700, Bongkeun Kim wrote:
> Hello,
>
> I had no problem to render images with transparent background with
> povray 3.6 and vmd 1.8.7. In povray, I used "+FN +UA" options to
> generate transparent png file.
> But this is not working anymore after installing VMD 1.9. Pov-ray
> always renders black background ignoring +UA option.
> Do you know how I can solve this problem?
> This problem was originated from 1.9 beta.
> Thank you.
> Bongkeun Kim
> bkim_at_chem.ucsb.edu
> 

-- 
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