VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Mon May 03 2021 - 16:10:00 CDT

Hi,
  When working with one of the well supported ray tracing engines,
it should not be necessary to have the VMD graphical representation
triangle mesh tessellation resolution set very high. In most cases,
the default resolution setting will be sufficient for good quality
renderings. This is in part due to the fact that the ray tracing
engines do pixel-rate lighting calculations, with interpolated
surface normals, so increasing the density of triangulation only
helps rendering of geometry with very tight curvature. As you've
described, setting these values too high can be counterproductive,
if taken too far. It is especially costly to rendering performance.
I should note that unless you have a specific reason not to, you'll
get generally better performance by using the "TachyonInternal"
renderer that also works entirely from memory, and avoids the time
required to write the scene to disk and then parse it for rendering.

Best,
  John Stone
  vmd_at_ks.uiuc.edu

On Sun, May 02, 2021 at 11:55:07PM +0200, Vlad Cojocaru wrote:
> It actually worked by lowering the resolution of the representations ....
> Reducing it from 30 to 15 for all reps lead to a 10 fold decrease in the
> size of the scene file and the rendering was successful. The lower rep
> resolution does not affect that much the image.
>
> Best,
> Vlad
>
> On 2 May 2021 20:10:50 CEST, Vlad Cojocaru
> <vlad.cojocaru_at_mpi-muenster.mpg.de> wrote:
>
> Dear all,
>
> I am trying to render a very complicated scene in VMD (1.9.4a51) with
> shadows and ambient occlusion on. The scene contains many simulation
> frames superimposed with a number of high resolution representations ...
> Tachyon creates a scene description file that is 25 GB large but it
> fails to produce the targa file although it says "rendering complete"
> and no error message is given. With povray, the ".pov" file is huge (56
> GB) and the targa image is also not produced.
>
> Can anyone give me any advice on how to best render such a complicated
> scene into a high resolution image ?
>
> Thanks
>
> Best wishes
> Vlad
>
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity. 

-- 
NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
http://www.ks.uiuc.edu/~johns/           Phone: 217-244-3349
http://www.ks.uiuc.edu/Research/vmd/