TrackIR 4:PRO camera attached to laptop monitor
|Type||Video game controller|
TrackIR is an optical motion tracking game controller for Microsoft Windows, created by NaturalPoint Inc. that tracks head motions with up to six degrees of freedom (6DOF) in later models, allowing handsfree view control for improved game immersiveness and situational awareness. Head position and orientation are measured by a purpose-built video camera, mounted on top of the user's monitor, which observes invisible infrared (IR) light (hence the name) reflected or emitted by markers on a rigid model worn by the user. TrackIR software is used to access and control the camera, as well as adjust tracking and manage game profiles. The ratio of actual head movement to virtual head movement can be changed, allowing the virtual head to turn 180 degrees whilst the user still looks at the monitor.
TrackIR has promoted and established head tracking in PC games, achieving support from many developers, particularly those involved in the simulation genre. In the process its interface has become the de facto standard for head-tracking game view control, although other commercial and non-commercial solutions exist.
|Model||Sensor resolution||FPS||Angle||Subpixel precision||DOF||Released||Latest software|
|TrackIR 1||60k pixels (e.g. 300×200)||60||33||2||2001||Version 3.x|
|TrackIR 2||60k pixels (e.g. 300×200)||100||33||2||2003||Version 3.x|
|TrackIR 3||355×288||80||33||2 or 6||2004||Version 4.x|
|TrackIR 3:PRO||355×288||120||33||2 or 6||2004||Version 4.x|
|TrackIR 4:PRO||355×288 (sub-sampled at 710×288)||120||46||1/20th||6||2005||Version 4.x|
|TrackIR 5||640×480||120||51.7||1/150th||6||2009||Version 5.x|
TrackIR cameras have a monochrome sensor with an on-board programmable logic device which pre-processes grayscale video into a thresholded binary video. This is sent to the computer via USB and further processed by TrackIR software to locate markers and from this estimate head position and orientation, all using only a small amount of bandwidth and CPU.
Tracking is made possible by the user wearing one of three different types of models. A single dot can be used for 2DOF, typically placed on the tip of a baseball cap, while 6DOF requires a special rigid model with three markers. Of the 6DOF models, the TrackClip model is intended to be cap mounted, with reflective material used for markers, and the TrackClip PRO model is headset mounted, with infrared LEDs used for markers.
The front of the camera has a plastic infrared filter which appears black, this reduces the brightness of non-IR light sources. This allows infrared light reflected or emitted by trackable objects on the user to be better isolated and tracked.
The TrackClip requires infrared LEDs to be activated in the camera, which are directed towards the user, to illuminate the model's reflective markers. The power output of these LEDs is about 500 times lower than the ANSI safe limit for extended exposure (more than 16 minutes) so is no more harmful than ambient light.
As of 2009 there are around 100 TrackIR Enhanced games that can natively use TrackIR cameras for view control with up to six degrees of freedom. Most of these have a simulation focus, belonging to flight and driving genres, with a small number of first person shooters and more casual games. Some popular TrackIR Enhancement games include ArmA: Armed Assault, ArmA 2, ArmA 3, GTR - FIA GT Racing Game 2, Race Driver: GRID, Test Drive Unlimited, iRacing, Euro Truck Simulator 2, Lock On: Modern Air Combat, Microsoft Flight Simulator X, IL-2 Sturmovik, Live For Speed, Enemy Engaged 2, Falcon BMS 4.32, Falcon 4.0: Allied Force, Rise of Flight: The First Great Air War, Newest builds of FreeSpace 2 Source Code Project, Aces High II, Jumpgate: The Reconstruction Initiative, World War Two Online and theHunter.
The TrackIR software has a games list that must be kept up-to-date for the latest TrackIR Enhanced games to be supported. This list is also used for assigning profiles, by default each game uses one of four common profiles, Default Profile, Combat Flight, Flight and Racing. Custom profiles can be created with control over numerous tracking settings, including the model type, smoothing, axis acceleration curves and hotkeys.
NaturalPoint have a record of strong online community involvement, providing technical support for supported games not only on their own forums but also across many game community forums.
Game developers can add TrackIR support to their game by applying for NaturalPoint's free TrackIR SDK, which is available under contract to, "developers who are producing games and simulations that will be sold as commercial products to the public." The interface has been described by developers as very simple and easy to implement.
The OptiTrack SDK shares the same camera interface as TrackIR software, providing low level access to the camera data. It is freely available for download and capable of producing 6DOF data for all NaturalPoint cameras but is not intended as an alternative to the TrackIR SDK, lacking the TrackIR software's convenient customization and profile management features. Despite TrackIR software sharing the same camera interface as the OptiTrack SDK, it cannot produce 6DOF data for TrackIR 1 and 2 cameras and does not support them beyond version 3.x.
Input device emulation
Unofficial support is available for several third-party programs that can be used to separately emulate mouse (TIRMouse, only in games), keyboard (TrackMapper, yaw and pitch axes mappable), and joystick (TIR2Joy to PPJoy) controls. Only one control type can be emulated at a time and not in conjunction with view control in TrackIR Enhanced games.
Full mouse emulation was an important view control method used by early TrackIR software. Once TrackIR gained native support in many popular flight and driving simulation titles, the mouse emulation feature was removed from the main software. Mouse emulation is still available for the 4.x software as a separate utility program. This utility can only be used within games, and not for general Windows cursor control. Full mouse emulation is now only available in NaturalPoint's SmartNav software which requires a more expensive SmartNav camera, intended specifically for the accessibility market.
The original TrackIR product was an affordable assistive technology device used for Windows cursor control. An early customer provided feedback to NaturalPoint that the product could be used in some flight simulators. This prompted NaturalPoint to re-brand the original device as SmartNav and launch a new TrackIR with improved gaming features to specifically target the flight simulation market. TrackIR was embraced by PC flight simulation enthusiasts who saw it as a better alternative to a joystick hat switch for view control. The technology used in SmartNav and TrackIR was later extended to another brand called OptiTrack, creating a more affordable professional motion capture solution.
Between 2002 and 2005, five different TrackIR camera models were released with steadily improving specifications. Frame rate doubled and resolution increased substantially, resulting in more responsive and accurate tracking. In 2003 the NaturalPoint President (also the principle hardware engineer) described these improvements to the original TrackIR as, "not critical for flight and driving sims, but very important to other types of games like first person shooters."
Software for TrackIR 1 and 2 can track a single point, producing 2DOF, this was later expanded with version 3.x software to allow multi-point tracking for 6DOF but only with TrackIR 3 hardware. This feature requires the purchase of a Vector Expansion license which now comes pre-installed with the TrackIR 4:PRO.
The TrackIR 3 was split into a cheaper standard model and a more expensive PRO model but the cheaper model was abandoned for the next version, TrackIR 4:PRO.
The TrackIR 4:PRO departs from the previous models' clamshell case with a new slim compact design, not much bigger than the diameter of a golf ball. It has a wider field of view than its predecessors and a new base so it can be attached to flat panel displays.
The TrackIR 5 was introduced in early 2009 with a similar design as the TrackIR 4:PRO. It features a wider field of view and higher resolution tracking sensor than previous models.
NaturalPoint have filed five patent applications for optical motion tracking as a means of view control in virtual environments since 2005, but as of 2008 none have been issued. Their most recent application is a refinement of prior applications, focusing on view control in multiplayer virtual environments.
TrackIR interface with games
The proprietary TrackIR interface has become the de facto standard for view control in PC games and simulations and is only intended for use with TrackIR products. As NaturalPoint convinced more developers and games to support it, other devices inspired by the TrackIR have sought to access the same view control and been successful in reverse engineering the interface. This has allowed non-TrackIR devices to be used for view control, including common video devices like webcams.
Early on NaturalPoint updated the interface to require validation using text strings copyrighted by NaturalPoint, and only granted permission for use of the strings to game and simulation developers. This meant other applications wishing to use the interface without approval from NaturalPoint would have to risk potentially violating NaturalPoint's copyright. Proponents of third party head tracking devices which rely on the TrackIR interface for support in many titles believe the text strings are exempt and fall under fair use for the purposes of interoperability.
In October 2008 NaturalPoint changed the TrackIR interface and began encrypting the data stream sent to some new titles. Third party devices which had reverse-engineered the previous TrackIR interface were rendered incompatible with these new game titles due to the encryption. The older TrackIR-1 and TrackIR-2 products that use software drivers which are no longer maintained are also incompatible with titles using the new encrypted interface.
Some larger gaming and simulation titles still do not support the TrackIR interface natively, such as Microsoft Flight Simulator X. Microsoft Flight Simulator X requires the TrackIR to send view control data to it using Microsoft's own SimConnect interface. Eagle Dynamics, developer of DCS: Black Shark and other popular Flight Simulation titles, implemented an alternative view control interface alongside the TrackIR interface but limited it to supporting 3DOF at NaturalPoint's request.
TrackIR 4 Pro
Some reviewers found the TrackIR 4 Pro with TrackClip Pro bundle to be expensive at the $200–$220 price, while still considering it a worthwhile purchase for serious simulation users. As of June, 2009 the bundle is available for $120. Additionally, one review noted that the TrackIR 4 Pro runs at a temperature which they consider higher than normal when it is actively tracking. The manufacturer has indicated that this is within the products designed tolerance.
Some reviewers found the TrackClip PRO to have loose joints, be less durable than desired, and one was disappointed that it was unable to be positioned on the right side of the head, while still recommending the product.
Other solutions for head-tracking in PC games:
- FreeTrack, an open-source and free head-tracking software which users can build their tracking hardware with webcams and infrared LEDs cheaply. Freetrack is no longer maintained.
- FaceTrackNoIR, an open-source and free head-tracking software which requires only a webcam and no infrared LEDs.
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