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====== 6DOF Motion Tracking with Polhemus G4 ======

//Article by Daniel Fütterer//

//**Abstract:** Description of the electromagnetic motion tracking system G4 from the manufacturer Polhemus and its software.//


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The Polhemus G4 system enables position and orientation data to be tracked using magnetic sensors. Transmitters are placed in the room and measured/calibrated, the sensors are attached to the object to be measured and connected to wireless and portable hubs. These transmit the data to the PC, which in turn analyses this data or (as in our application) streams it into the network.

The manufacturer's software runs on Windows and Linux, is compatible with the game engine via coded UDP export [[https://unity.com/de|Unity]] and consists of several components for registration, calibration, monitoring and transmission (e.g. with named pipe or UDP). In addition, large parts of the software are open source, which enables the development of customised tools.

Under Linux, there is a suite of several programmes:

^ ^ ^
| g4devcfg: | Proprietary tool for configuring the Polhemus hardware (dongle and hub)| 
| g4track_lib: | Libraries for use with the other programmes| 
| createcfgfile: | Programme for creating the config files (hardware setup)| 
| g4display: | Graphical display of the sensor position and orientation| 
| g4term: | Textual output of the sensor data| 
| g4export (developed by Janis Streib): | Command line programme for transferring sensor data via OSC| 
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The software is used in combination with programmes such as Max/MSP or PureData, which are able to read out and process the OSC stream of sensor data.

An example application is realised in the project of student Lukas Körfer: [[https://edu.marlonschumacher.de/speaking-objects/|Speaking Objects]].

Own software developments: [[https://marlonschumacher.webo.family/index.php/s/8d8sJ2a9HpPiLbY|Max-Patches]]

Further developments by Janis Streib (incl. instructions):

  * [[https://git.marlonschumacher.de/user/streib|Gitblit-Übersicht]]
  * [[https://git.marlonschumacher.de/summary/~streib!g4_docker_builder.git|Docker_Builder]]
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For further resources, see the menu entry for Polhemus at [[https://marlonschumacher.webo.family/index.php/s/ZWRPKLL5eG9JieA|„Ressourcen“]] (Nextcloud)


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===== Comparison of different motion tracking systems =====

[[http://www-personal.umich.edu/~yangqi/NIME2012/papers/155_Final_Manuscript.pdf|Link]] (external)


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===== Demo Videos =====

{{ hardware:6dof-motion-tracking1.mp4?640x360 }}

//Pilot test for using the G4export software (Janis Streib) on a Raspberry PI to control a virtual mixer via [[https://www.cnmat.berkeley.edu/OpenSoundControl|OpenSoundControl]].//
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{{ hardware:6dof-motion-tracking2.mp4?360x640 }}

//Proof-of-concept: Use of the G4 system to control the avatar (head tracking) for the application [[https://github.com/marleynoe/Binauralix/releases|Binauralix]].// 


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===== Official videos of the manufacturer =====

Note: external links to YouTube

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{{tag>Human-Computer-Interaction Motion-Capture}}