From: John Stone (
Date: Thu Feb 17 2005 - 16:13:26 CST

  VMD doesn't know anything about your Intersense tracker at all.
Since you specified "cavetracker" and "cavebuttons", it is merely
using the integer tracker index to ask the CAVE library to get
coordinates etc, it doesn't have any knowledge of which tracker is
what other than their index. As such, the only valid configuration
in a cave would be something like this:

# Configuration for the NCSA CAVE trackers
device cavetracker cavetracker://local/cave
scale 1.0
offset 0.9 -4.0 -1.0
device cavebuttons cavebuttons://local/cave:0,1,2,3

# if you have more than one CAVE wand, display 2nd one as a pointer..
device cavetracker2 cavetracker://local/cave:1
scale 1.0
offset 0.9 -4.0 -1.0

I assume you've run other CAVE apps successfully on this system?
Perhaps the coordinate system transforms in your .caverc file are
different than what NCSA likes to use?

  John Stone

On Mon, Feb 14, 2005 at 10:36:03PM -0500, Luis Rosales wrote:
> Hi all,
> I am trying to configure the tracker for our VR auditorium. We dont have VRPN,
> but we have CAVElib. As a tracking system we have the infamous Intersense-900
> with the head tracking system and the wand (5 buttons + joystick).
> o I have started vmd (vmd 1.8.3b4 on a SGI onyx) with the -caveforms option
> and the default vmdsensors file:
> device cavetracker cavetracker://local/cave
> scale 1.0
> offset 0.9 -4.0 -1.0
> device cavebuttons cavebuttons://local/cave:0,1,2,3
> I also created a "grab tool" with the tools form.
> My problem is that from what I have seen, VMD is responding to the movement of
> the head sensor as it would expected for the wand (head movement rotates/moves
> the molecule around), while the wand seems to change the "angle/point of view"
> I have modified the .vmdsensors/.caverc without any success....
> So I have a couple of questions:
> 1. I have read the relevant section of the manual, but I still dont have clear
> the role of the different parts of the USL format, like:
> is the name expected to be a generic one as in //local/cave or it can be
> more specific like in //local/IS900 or //local/trackd?
> the number of nums in the cavebuttons is equal to the number of buttons on
> the the tracker?
> If any of you have info about a more detailed reference to the USL format, it
> would be really appreciated!!
> 2. If VMD is really loading the tracking system "upside-down", maybe I need to
> look in other configuration files different from the .vmdsensors and the .caverc?
> I did a search on the vmd-l archive, I was unable to find an answer to my
> problem, but I found that several people had used the IS900 system before, I
> would like to know if some of you have found this problem before...
> As usual, thanks in advance for your help and time.
> Luis

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