From: John Stone (
Date: Thu Mar 31 2016 - 10:27:56 CDT

  The standard 3DConnexion X-Windows and MS-Windows message protocol
doesn't have a way of distinguishing between multiple 6DOF input devices,
so there's an inherent problem with the normal input processing path with
multiple devices. Fortunately, there is more than one way to talk to
a SpaceNavigator.

To use one of them as a "Tug" tool, I think that you'll
want to have it driven via VRPN, which (should) talk to the device using
low-level USB or OS kernel event I/O that bypasses the windowing system.

Another option which isn't quite ready yet, but that I've got half-implemented
would be to use a new input module for VMD that uses low-level OS kernel
event I/O to talk to the SpaceNavigator and joysticks on Linux. This
approach bypasses both VRPN and the Windowing system provided mechanisms
for talking to input devices, which is needed for handling arbitrary numbers
of input devices, devices that are not supported by conventional APIs
(e.g. VR HMDs and similar) and to get lower latency, and perhaps
most importantly, for "hot plugging" support which is something that
neither VRPN nor the windowing systems provide presently.


On Thu, Mar 31, 2016 at 11:33:46AM +0200, Jesper Lykkegaard Karlsen wrote:
> Dear all,
> I am new to VMD, so sorry for any major misunderstanding in advance.
> I want to use VMD together with two SpaceNavigators. One to control a
> "tug-Tool" and the other to control the view.
> Although, so it seems like the two SpaceNavigators are inseparable and
> both load the same mode.
> Is it possible discriminate between the two, so they can have different
> modes loaded at the same time?
> Thanks,
> Jesper
> --
> Jesper Lykkegaard Karlsen
> Scientific Computing
> Centre for Structural Biology
> Department of Molecular Biology and Genetics
> Aarhus University
> Gustav Wieds Vej 10C
> 8000 Aarhus C
> E-mail:

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