From: John Stone (johns_at_ks.uiuc.edu)
Date: Fri Feb 12 2010 - 11:32:37 CST

Hi,
  For the GUIs, have you considered using a hand-held device like a
wireless tablet to control VMD? When NCSA had a CAVE setup in
my building, we would either redirect the X11 GUIs to a console at
the back wall of the CAVE, or we would setup a very simple Tk GUI
that would trigger the most useful actions within VMD via a remote
socket connection. You can do things like that with just a little
bit of scripting without having to change any of the core VMD code.
Having a tablet device is handy, as they are often easier to interact
with than a 3-D immersive style GUI, particularly for things that
are awkward to represent in the form of 3-D buttons or menu objects
that you have to pierce with a tracker. I find that retaining a simple
2-D GUI controlled by a hand-held device is more convenient than
going 100% into VR-only-GUIs...

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Fri, Feb 12, 2010 at 09:24:58AM -0600, Dipesh Bhattarai wrote:
> Thanks for your reply. The problem was with transformation of the tracker
> position with transformation_matrix in the display device. It is solved
> now.
>
> As for the subclassing VMD tracker class, I let VR Juggler handle all the
> detail about accessing and updating the tracker status. I use the
> information received from VR Juggler and pass that to VMD. So far,
> selection works fine. But adding programmability to the selection is
> creating problem. That is more to do with lack of GUI in the
> multiprojector environment than anything other. I still don't know how to
> proceed with that. Buttons in the wand are all used up for one
> functionality or the other.
>
> Thanks,
>
> Dipesh
>
> On Fri, Feb 12, 2010 at 12:26 AM, John Stone <johns_at_ks.uiuc.edu> wrote:
>
> Hi,
> Have you implemented VMD tracker subclass(es) for your 3-D tracker?
> I would begin by doing that, otherwise you may be way off in
> your coordinate system. If you have a tracker subclass implemented,
> then you should be able to use the various "tool" modes in the
> VMD tool menu to see the position of your tracker on the screen,
> and to interact with button events etc. Once you have that sorted
> out, you could implement other interactions beyond what's already there.
> Without seeing the entirety of the code you've written, it is difficult
> to judge what you're having trouble with. Unless VMD is actually
> drawing
> the pointer for you via the normal class hierarchy, I cannot say
> whether what you're seeing on the screen with your pointer
> is even relevant as far as the pick calls go. If you can provide me
> with the code you're working with, I can try and give you suggestions
> for solving your problem as time allows.
>
> Cheers,
> John Stone
> vmd_at_ks.uiuc.edu
>
> On Mon, Feb 08, 2010 at 10:57:03AM -0600, Dipesh Bhattarai wrote:
> > Hello all,
> >
> > I am trying to select subset of the molecule using a 3D pointing
> device.
> > The device is tracked by Intersense IS-900 tracking system and is
> accessed
> > through VRPN. I am using VR Juggler to tie the VMD with the
> multiprojector
> > display and the device. I call app->pickList->pick_check() method
> to see
> > if there are any atoms near the current position of the 3D pointing
> > device. Even though the location of the cursor looks to be
> overlapping,
> > the method does not actually return anything. Sometime it seems to
> select
> > something, but the picked items does not actually correspond to the
> item
> > near the cursor position. I believe it is because the tracker
> position and
> > VMD use different coordinate systems.
> >
> > How do I transform the 3D cursor position so that it correspond to
> the
> > coordinate system VMD use? I would appreciate any pointer to the
> solution.
> >
> > Thanks,
> > Dipesh
> >
> > --
> > Dipesh Bhattarai, PhD
>
> --
> NIH Resource for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> Email: johns_at_ks.uiuc.edu Phone: 217-244-3349
> WWW: http://www.ks.uiuc.edu/~johns/ Fax: 217-244-6078
>
> --
> Dipesh Bhattarai, PhD

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078