VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Wed Mar 12 2003 - 13:53:32 CST

Hi Sanjeev,
  The best looking transparency is achieved through the use of
ray tracing packages such as Raster3D, POV-Ray, and Tachyon.
VMD itself uses a simple polygon stippling mechanism to approximate
the transparency effect while retaining 100% of its normal rendering speed.
Also, this means that Tachyon can get by with shallower frame buffers
since it doesn't need to use the alpha channel, leaving more framebuffer
memory for things like antialiasing, stereo, etc. The polygon stippling
mechanism is fast, but not the same level of quality you'd get from
a ray tracer or from alpha blended transparency with correct depth sorting.
Let us know if you need help exporting your scenes to one of the supported
ray tracing packages.

Thanks,
  John Stone
  vmd_at_ks.uiuc.edu

On Tue, Mar 11, 2003 at 09:48:43AM +0530, Sanjeev B.S. wrote:
> Hello,
> I would like to use VMD (at least as a starting point) to make
> transperent images (a couple of eg are given in PS). When I use opacitiy
> in Materials, the quality of transperency doesn't seem to be the same as
> in the example cases. Could anyone suggest me a way of doing this please?
> Thanks in advance,
> -Sanjeev
>
> PS:
> 1. http://wwwchem.leidenuniv.nl/metprot/armand/002l.html
> 2. http://wwwchem.leidenuniv.nl/metprot/armand/008l.html 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
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