From: John Stone (
Date: Wed Apr 03 2002 - 09:53:30 CST

Dear Marc,
  Not all of the rendering options truly support orthographic
rendering, some of the renderers (such as Tachyon for example)
render perspective views just fine, but don't have the ability
to render orthographic views. I have added orthographic rendering
code to Tachyon recently, but I need to finalize the scene file
format changes for it and make matching changes in VMD to support
it. If you like, I can send you a note as soon as this is available
for testing. The Renderman export in our VMD 1.8 alpha code will also
provide correct orthographic views.

The POV-Ray and snapshot options are currently your best bet for
getting 100% matching views, but you'll need to be running VMD 1.7.1
or later to have all of the POV-Ray fixes.

The remaining issue you mention about POV-Ray being too dark may have
to do with having shadows enabled. I believe one can tell POV-Ray
not to render shadows (this is what I do with Tachyon, to make the
images look more like what VMD and OpenGL produce...)

Let me know if I can be of further assistance.

  John Stone

On Wed, Apr 03, 2002 at 10:43:28AM +0100, Marc Baaden wrote:
> Hi,
> following from the last mail on this list I also wanted to ask
> a question which nags me for some time.
> In some cases it is useful to show orthographic views of your system
> (ie one view + view rotated by 90deg around any of the axes).
> I usually use Raster3D to render my images, but I noticed that there is
> a slight difference in size.
> Eg if you put the 2 views side-by-side or one over the other, it's not
> exactly the same size, which it should be.
> I guess this is due to perspective distortion (even though I chose ortho-
> graphic from the Display menu).
> Is there a way arount this ?
> If I got the last eMail right what should work is
> - using tachyon
> - using snapshots
> ?- using povray export ? (I don't like this 'cause it comes out too dark on
> my system)
> Also is there a way of including a scale/ruler eg as in Ribbons
> (I know about the grid, but that's a bit too much just to indicate
> a scale).
> And also I was confused, if you want to make sure that different
> molecules get the same scaling, which are the values you have to set
> and how ?
> Thanks in advance,
> Marc Baaden
> --
> Dr. Marc Baaden - Laboratory of Molecular Biophysics, Oxford University
> - ICQ# 11466242 -
> FAX/Voice +49 697912 39550 - Tel: +44 1865 275380 or +33 609 843217

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