From: Robin Betz (
Date: Wed Jan 22 2020 - 13:51:57 CST

Hi Sebastian,

I've had similar problems where the render window doesn't update in time
for the snapshot to be captured.
I believe premature optimization on the part of the display driver is to
The environment variable VMDMSECDELAYHACK sets the number of milliseconds
between render calls. I have found values of 50-100 can fix this problem
for me, although you will want to find the sweet spot between rendering at
a reasonable rate and getting frame skipping.

Hope this helps,

On Wed, Jan 22, 2020 at 11:33 AM Sebastian Reiter <> wrote:

> Hi,
> I am trying to make a movie of a protein with the ViewChangeRender and
> Movie Maker plugins and the snapshot render command. Particularly, I
> would like to slowly zoom into a specific site of a protein. However,
> snapshot sometimes seems to randomly zoom out a little from the current
> viewpoint. This causes the movie to stutter because the zooming motion
> is not continuous but interrupted by randomly offset frames.
> I know that it has something to do with snapshot, because a dry run with
> Movie Maker looks just fine. Also, the same thing happens, when I render
> a static scene with snapshot.
> Has anyone experienced this kind of issue before and knows a solution?
> If possible, I would like to stay with snapshot, because I am quite
> happy with the look and because more sophisticated rendering engines are
> too slow on my machine for a movie with a few hundred frames.
> I am using VMD 1.9.3 on a Ubuntu 18.04 64bit machine. The startup
> information of VMD says the following about the available graphics:
> Info) Multithreading available, 4 CPUs detected.
> Info) CPU features: SSE2 AVX AVX2 FMA
> Info) Free system memory: 3816MB (48%)
> Info) No CUDA accelerator devices available.
> Warning) Detected X11 'Composite' extension: if incorrect display
> occurs
> Warning) try disabling this X server option. Most OpenGL drivers
> Warning) disable stereoscopic display when 'Composite' is enabled.
> Info) OpenGL renderer: Mesa DRI Intel(R) HD Graphics 630 (Kaby Lake
> GT2)
> Info) Full GLSL rendering mode is available.
> Info) Textures: 2-D (16384x16384), 3-D (512x512x512),
> Multitexture (8)
> Thanks in advance and best regards
> Sebastian