Tracking Systems

Recommendations

There are three specific Position Tracking systems that are recommended. Choosing a particular model depends on the factors described below, as well as availability.

Recommendations:

• NaturalPoint Tracking Tools Plus package provides 6 IR cameras plus the reflective balls, and calibration tools requied for a good tracking environment. This has been the traditional system of the IQ-station community, so there is a lot of experience with it.
• NaturalPoint Trio system provides 3 IR cameras in a fixed bar arrangement. This saves from having to do calibration for the camera arrangements. These are just now being tested for use with IQ-stations.
• AR-Tracking SmartTrack system provides 2 IR cameras in a fixed bar arrangement, also saving from calibration. These too are just now being tested for use with IQ-stations. Note that these are slightly pricier than the other two options.

Position Tracking Technologies

There are many different technologies can can be employed to provide full six Degrees of Freedom position tracking — three translational degrees and three rotational degrees — a requirement for physical immersion. Three common techniques for low-cost systems are:

• Optical
• Sonic
• Electromagnetic

Each method has it's own pros & cons. We recommend the book Understanding Virtual Reality for details on these technologies.

All three of our recommended technologies use optical tracking methods in the infrared spectrum (IR).

Experience with Specific Models

Optical Tracking

• NaturalPoint OptiTrack 6-camera TrackingTools Bundle
  • Pro: Complete Hardware/Software solution
  • Pro: Moderate Cost — ~$5600
  • Pro: Uses standard VRPN interface
  • Con: Requires MS-Windows-based PC for software
  • Con: Requires Lengthy calibration when cameras are re-adjusted (or accidentally moved)
  • used at Indiana University
  • used at Desert Research Institute
  • used at UC-Davis
  • used at INL
• NatrualPoint OptiTrack Trio]
  • Pro: Complete Hardware/Software solution
  • Pro: Low Cost — ~$2500
  • Pro: Uses standard VRPN interface
  • Pro: No Calibration required
  • Con: Requires MS-Windows-based PC for software
  • tested at INL
  • tested at Indiana University
• A.R.T. SMARTTRACK
  • Pro: Complete Hardware/Software solution
  • Pro: No Calibration required
  • Pro: No additional PC required
  • Con: Somewhat higher cost (~$10000 — ~$7500 academic)
  • in use at Indiana University
  • in use at Idaho National Laboratory

Electromagnetic Tracking

• Polhemus Patriot Wireless
  • Pro: No line-of-sight limitations — uses EM tracking technology
  • Con: Not very robust
  • Con: tracking markers are somewhat bulky
  • Con: metal in the vicinity negatively affects performance
  • Con: Somewhat higher cost (~$9000 for a two-marker system)

    NOTE: price reflects that the system effectively needs two "receivers"

  • tested at Indiana University

Game Technology Tracking

While the example game system technologies listed here both use optical means of tracking, we include them as a separate category due to the clear qualitative differences with professional tracking systems.

• MicroSoft Kinect
  • Pro: really, really low-cost ($150)
  • Con: not sufficiently robust for a research workflow
  • Con: requires extra technical expertise to setup
• Nintendo WiiMote
  • Pro: really, really low-cost ($50)
  • Con: not sufficiently robust for a research workflow
  • Con: requires extra technical expertise to setup