This page contains a toolkit for
enabling 3D tracking (from devices such as the Ascension, Polhemus and
Intersense Trackers) in Blitz3D
The diagram below shows how it works. Tracker data read from the
(the PC physically connected to the 3-space tracker) via TrackerDaemon
is sent to a Linux
PC that is normally running Trackd Server. Trackd Server makes the
tracking data available for CAVE
programs to use. Blitzvars is a CAVE program that reads the tracker
data and sends it to the Blitzserver program. Blitzvars is actually a
modification of the standard CAVEVars program. Blitzserver will listen
for connections from your Blitz3D program and start sending data to the
program upon connection.
So here is the sequence of things you need to do to set up and run a
- Download the library below and unzip it on your Windows PC that
will run your Blitz3D program.
- Copy the BlitzVars folder to the Linux PC which has the CAVE
Trackd server runnning.
- Compile BlitzVars and Blitzserver on the Linux PC by typing: make
- Run Blitzserver by typing: Blitzserver
- Run Blitzvars by typing:
- Now on the Windows PC, bring up the Blitz3D demo TRACKED_DEMO.bb
and run it in
Blitz3D or compile to a self-contained executeable. When prompted for
the tracker's hostname, give it the IP address of the Linux PC that is
running the Blitzvars/Blitzserver.
- Now, when you wave your wand or move your head with the head
there should be a change in the scene and the wand in the simulation.
press 1 to go back into Mono and 2 to go into Stereo.
Note also that there is a second demo: TRACKED_FRAME_STABLE_DEMO.bb.
This is essentiallty the same as TRACKED_DEMO except that it also
incorporates code to maintain a consistent frame rate regardless of the
speed of your computer. This is actually the best place to start to
develop your own applications. TRACKED_DEMO was provided because it is
an easier body of code to understand.
Also note that the actual library for rendering stereo and for handling
the tracking are: BlitzGeoWallStereoLib.bb and BlitzCaveTrackerL:ib.bb
respectively. Both of these are bundled into the ZIP file that you
download. BlitzGeoWallStereoLib is maintained at this website
Final Note: the correlation
between the tracking and the stereo computer graphics is not perfect,
yet. This is because Blitz3D does not yet support off-axis projections.
This is under development by the Blitz developers.
For support, please post a message on: www.evl.uic.edu/cavern/forum