Difference between revisions of "Positional tracking"
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| − | ''' | + | [[File:PnO tracking of a robot.png|thumb|Position and orientation tracking using lasers]] |
| + | [[File:Worldsense positional tracking.png|thumb|Figure 1. WorldSense positional tracking. (Image: UploadVR)]] | ||
| + | '''Positional tracking''', also known as 6DOF tracking and position and orientation tracking (PnO tracking), is tracking of an object's [[position and orientation]] in 3D space. It can be used to track headsets and handheld devices. It is useful for providing position and orientation data to apps so that they can render the virtual camera and objects in the right places. It is used in devices like the [[Meta Quest 2]]. It is also known as 3D tracking, for three dimensions of classical space that objects are tracked in. | ||
| − | + | It can be done using a number of different hardware technologies, such as [[electromagnetic tracking]] or [[camera-based tracking]]. Methods of camera-based tracking include methods using [[SLAM]] or [[VIO]]. Electromagnetic tracking is faster and typically more precise, but has interference problems. Camera-based tracking is slower, more expensive to implement, but is more reliable in a variety of environments, and may not need an external tracking system. | |
| − | It is | + | Position can be represented in a computer system using a 3D vector. Rotation can be represented using a quaternion. It can be done in theory using [[multilateration]] using lasers.<ref name="b754">{{cite journal | last=Nitsche | first=Jan | last2=Franke | first2=Matthias | last3=Haverkamp | first3=Nils | last4=Heißelmann | first4=Daniel | title=Six-degree-of-freedom pose estimation with µm/µrad accuracy based on laser multilateration | journal=Journal of Sensors and Sensor Systems | publisher=Copernicus GmbH | volume=10 | issue=1 | date=2021-02-19 | issn=2194-878X | doi=10.5194/jsss-10-19-2021 | doi-access=free | pages=19–24}}</ref> PnO tracking is related to rotation tracking, which uses [[3DOF]] of space. It is used in an [[absolute positioning system]]. It is known as 6DOF tracking, because of the 6 degrees of freedom (DOF), which are ways that an object can move: horizontally, vertically, depthwise, and three rotation movements: pitch, roll, and yaw. |
| + | __NOTOC__ | ||
| + | == Methods == | ||
| + | * [[Markerless inside-out tracking]], which is [[camera-based tracking]] (SLAM/VIO)- This is used on headsets such as Meta Quest headsets and the [[Project North Star]]. An open source method is [[Basalt]]. Markerless inside-out tracking can use visible light or infrared light, which can be artificially emitted. | ||
| + | * [[Marker-based tracking]] - Camera based tracking that uses markers in the environment, which is simpler to implement. | ||
| + | * [[Electromagnetic tracking]].<ref name=3duibook/> Electromagnetic tracking requires an external source. It gets jittery when there is metal around, like a metal laptop computer. Magnetic tracking is typically wired, but it does not have to be. | ||
| + | * [[UWB tracking]] | ||
| + | * [[Mechanical tracking]]<ref name=3duibook/> | ||
| + | * [[Ultrasonic tracking]]<ref name=3duibook>[[3D User Interfaces: Theory and Practice]], 1st edition, page 97</ref> | ||
| + | * Visible light-based tracking | ||
| + | * Infra-red based tracking | ||
| − | + | ==Magnetic tracking== | |
| − | + | 240Hz is generally sufficient if using magnetic tracking with no filtering. | |
| − | |||
== History == | == History == | ||
3D tracking has been used for motion capture for 3D animated movies. | 3D tracking has been used for motion capture for 3D animated movies. | ||
| − | The 3DOF regime of cheap tracking was embraced by [[Oculus VR]] with the original [[Oculus Rift]]. | + | The 3DOF regime of cheap tracking was embraced by [[Oculus VR]] with the original [[Oculus Rift]]. The CV1 of the Oculus Rift (and the DK2) use [[constellation tracking]], which is a complex method of 6DOF tracking added on to a robust 3DOF system. |
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==References== | ==References== | ||
{{Reflist}} | {{Reflist}} | ||
| − | [[Category: | + | [[Category:Position and orientation tracking]] |
| + | [[Category:Control peripherals]] | ||
Latest revision as of 02:51, 27 February 2025
Positional tracking, also known as 6DOF tracking and position and orientation tracking (PnO tracking), is tracking of an object's position and orientation in 3D space. It can be used to track headsets and handheld devices. It is useful for providing position and orientation data to apps so that they can render the virtual camera and objects in the right places. It is used in devices like the Meta Quest 2. It is also known as 3D tracking, for three dimensions of classical space that objects are tracked in.
It can be done using a number of different hardware technologies, such as electromagnetic tracking or camera-based tracking. Methods of camera-based tracking include methods using SLAM or VIO. Electromagnetic tracking is faster and typically more precise, but has interference problems. Camera-based tracking is slower, more expensive to implement, but is more reliable in a variety of environments, and may not need an external tracking system.
Position can be represented in a computer system using a 3D vector. Rotation can be represented using a quaternion. It can be done in theory using multilateration using lasers.[1] PnO tracking is related to rotation tracking, which uses 3DOF of space. It is used in an absolute positioning system. It is known as 6DOF tracking, because of the 6 degrees of freedom (DOF), which are ways that an object can move: horizontally, vertically, depthwise, and three rotation movements: pitch, roll, and yaw.
Methods[edit]
- Markerless inside-out tracking, which is camera-based tracking (SLAM/VIO)- This is used on headsets such as Meta Quest headsets and the Project North Star. An open source method is Basalt. Markerless inside-out tracking can use visible light or infrared light, which can be artificially emitted.
- Marker-based tracking - Camera based tracking that uses markers in the environment, which is simpler to implement.
- Electromagnetic tracking.[2] Electromagnetic tracking requires an external source. It gets jittery when there is metal around, like a metal laptop computer. Magnetic tracking is typically wired, but it does not have to be.
- UWB tracking
- Mechanical tracking[2]
- Ultrasonic tracking[2]
- Visible light-based tracking
- Infra-red based tracking
Magnetic tracking[edit]
240Hz is generally sufficient if using magnetic tracking with no filtering.
History[edit]
3D tracking has been used for motion capture for 3D animated movies.
The 3DOF regime of cheap tracking was embraced by Oculus VR with the original Oculus Rift. The CV1 of the Oculus Rift (and the DK2) use constellation tracking, which is a complex method of 6DOF tracking added on to a robust 3DOF system.
References[edit]
- ↑ Nitsche, Jan; Franke, Matthias; Haverkamp, Nils; Heißelmann, Daniel (2021-02-19). "Six-degree-of-freedom pose estimation with µm/µrad accuracy based on laser multilateration". Journal of Sensors and Sensor Systems (Copernicus GmbH) 10 (1): 19–24. doi:10.5194/jsss-10-19-2021. ISSN 2194-878X.
- ↑ Jump up to: 2.0 2.1 2.2 3D User Interfaces: Theory and Practice, 1st edition, page 97