VR & AR Wiki - User contributions [en]

Inside-out tracking

2018-03-20T03:57:35Z

Cunningham: these aren't QR codes

{{stub}}
{{see also|Markerless inside-out tracking‎|Positional tracking}}
[[File:Inside out vs. outside in tracking.png|thumb|Figure 1. Inside-out vs. outside-in tracking (Image: Ishii, 2010)]]
[[File:F2Ak4iE.jpg|thumbnail|Figure 2. Early [[Lighthouse]] prototype, an inside-out tracking system with 2-dimensional barcodes as [[fiducial markers]].]]
[[File:Acer mixed reality headset inside-out.png|thumb|Figure 3. Inside-out tracking HMD (image: www.wareable.com)]]

==Introduction==
Inside-out tracking is a method of [[positional tracking]] commonly used in [[virtual reality]] (VR) technologies, specifically for tracking the position of [[head-mounted display|head-mounted displays]] (HMDs) and motion controller accessories. It differentiates itself from [[outside-in tracking]] by the location of the cameras or other sensors that are used to determine the object’s position in space (Figure 1). In inside-out positional tracking, the camera or sensors are located on the device being tracked (e.g. HMD) while in outside-out the sensors are placed in a stationary location. <ref name=”1”> Ribo, M., Pinz, A. and Fuhrmann, A.L. (2001). A new optical tracking system for virtual and augmented reality applications. Instrumentation and Measurement Technology Conference Proceedings</ref> <ref name=”2”> Boger, Y. (2014). Positional tracking: "Outside-in" vs. "Inside-out.” Retrieved from http://vrguy.blogspot.pt/2014/08/positional-tracking-outside-in-vs.html</ref> <ref name=”3”> Ishii, K. (2010). Augmented Reality: Fundamentals and nuclear related applications. Nuclear Safety and Simulation, 1(1)</ref>

A VR device using inside-out tracking looks out to determine how its position changes in relation to the environment. When the headset moves, the sensors readjusts its place in the room and the virtual environment responds accordingly in real time. This type of positional tracking can be achieved with or without markers placed in the environment. The latter is called [[markerless inside-out tracking]]. <ref name=”4”> Langley, H. (2017). Inside-out v Outside-in: How VR tracking works, and how it's going to change. Retrieved from https://www.wareable.com/vr/inside-out-vs-outside-in-vr-tracking-343</ref>

The cameras (or any other optical sensors) that are placed on the HMD observe features of the surrounding environment. When using markers, these are designed to be easily detected by the tracking system and placed in a specific area. These [[fiducial markers]] include primitive shapes like points, squares, and circles (Figure 2). QR codes are an example of positional markers that can be placed in the outside world to serve as reference points for the tracking camera. Inside-out positional tracking can also be achieved using infra-red (IR) markers and a camera that is sensitive to this type of light. In case of using markers, the inside-out system works only as long as it can detect the markers. If these are out of its field of view, positional tracking will be affected. <ref name=”2”></ref> <ref name=”3”></ref> <ref name=”5”> Mehling, M. (2006). Implementation of a Low Cost Marker Based Infrared Optical Tracking System. PhD thesis, Fachhochschule Stuttgart</ref>

With markerless inside-out tracking - a method based on natural features - uses distinctive characteristics that originally exist in the environment to determine position and orientation. The system’s algorithms identify specific images or shapes and uses them to calculate the device’s position in space. Data from accelerometers and gyroscopes can also be used to increase the precision of positional tracking. <ref name=”3”></ref> <ref name=”6”> Boger, Y. (2014). Overview of positional tracking technologies for virtual reality. Retrieved from http://www.roadtovr.com/overview-of-positional-tracking-technologies-virtual-reality/</ref>

==Devices using inside-out tracking==
* ''See also: [[Markerless, inside-out tracking#Markerless inside-out tracking Devices|Devices using markerless inside-out tracking]]''

'''[[HTC Vive]] (including [[HTC Vive Developer Editions|developer editions]])'''

'''[[Microsoft HoloLens]]'''

'''[[Nintendo Wii Remote]] (not officially used for VR)'''

'''[[Samsung HMD Odyssey]]'''

==Inside-out tracking systems==
* ''See also: [[Markerless, inside-out tracking#Markerless, inside-out tracking Systems|Systems using markerless inside-out tracking]]''

'''[[Lighthouse]] - [[SteamVR]]'''

'''[[Nintendo Wii Sensor Bar]] (not officially used for VR)'''

[[Category:Terms]] [[Category:Technical Terms]]

==References==

Outside-in tracking

2018-03-20T03:55:59Z

Cunningham: Remove patently-false claims. I hate this paragraph, but removing the patently-false claims meant I had to reword it.

{{stub}}
{{see also|Markerless outside-in tracking|Positional tracking}}
==Introduction==
[[File:Outside in tracking.png|thumb|Figure 1. Outside-in tracking (Image: www.wareable.com)]]
[[File:Inside out vs. outside in tracking.png|thumb|Figure 2. Inside-out vs. outside-in tracking (Image: Ishii, 2010)]]

Outside-in tracking is a form of [[positional tracking]] and, generally, it is a method of optical tracking. When referring to [[virtual reality]] (VR), tracking is the process of tracing the scene coordinates of moving objects in real-time, such as [[head-mounted display|head-mounted displays]] (HMDs) or motion controller peripherals. <ref name=”1”> Ribo, M., Pinz, A. and Fuhrmann, A.L. (2001). A new optical tracking system for virtual and augmented reality applications. Instrumentation and Measurement Technology Conference Proceedings</ref>

Outside-in VR tracking uses cameras or other sensors placed in a stationary location and oriented towards the tracked object (e.g. a headset) that moves freely around a designated area defined by the intersecting visual ranges of the cameras (Figure 1). The object is therefore observed from outside by the fixed tracking device. Usually, the tracked object has a known set of markers that are essential for the calculation of its position relative to the sensors. Also, while this type of positional tracking can be achieved using the visible light spectrum, it is common to use infra-red (IR) markers and cameras that can detect that type of light. <ref name=”1”></ref> <ref name=”2”> Mehling, M. (2006). Implementation of a Low Cost Marker Based Infrared Optical Tracking System. PhD thesis, Fachhochschule Stuttgart</ref> <ref name=”3”> Boger, Y. (2014). Positional tracking: "Outside-in" vs. "Inside-out.” Retrieved from http://vrguy.blogspot.pt/2014/08/positional-tracking-outside-in-vs.html</ref>

Outside-in VR tracking's accuracy and performance are dependent on various factors like the quality of the optical sensors, tracking markers and targets, processing power, and tracking algorithms, all of which can vary greatly. <ref name=”2”></ref> <ref name=”4”> Wang, J.F., Azuma, R., Bishop, G., Chi, V., Eyles, J. and Fuchs, H. (1990). Tracking a head-mounted display in a room-sized environment with head-mounted cameras. Proceedings of SPIE 1990 Technical Symposium on Optical Engineering and Photonics in Aerospace Sensing, Orlando, Florida</ref>

Outside-in tracking using markers is a well-developed and researched technology. Indeed, a group of researchers (Pustka et al., 2012) built a positional tracking system of this kind using only unmodified off-the-shelf mobile phones. Also, an early two-camera tracking system was described by Madritsch and Gervautz in 1996, and a system that used synchronized IR cameras, able to distinguish 6D targets, was described by Dorfmüller in 1999. <ref name=”5”> Pustka, D., Hülb, J.P., Willneff, J., Pankratz, F., Huber, M. and Klinker, G. (2012). Optical Outside-In Tracking using Unmodified Mobile Phones. IEEE International Symposium on Mixed and Augmented Reality</ref>

The outside-in tracking system needs room calibration after the cameras or sensors are placed, and the data acquired by the system is processed on a computer. <ref name=”3”></ref> <ref name=”5”></ref> Besides its application in VR, this type of tracking is used in motion capturing, as in the case of the film industry. <ref name=”2”></ref>

Outside-in tracking functions as the inverse of [[inside-out tracking]] (Figure 2). While the former places the sensors in a stationary location to track the VR goggle, in the latter the sensors are placed on the goggles and the markers in stationary locations. <ref name=”3”></ref> <ref name=”7”> Ishii, K. (2010). Augmented Reality: Fundamentals and nuclear related applications. Nuclear Safety and Simulation, 1(1)</ref>

==Devices using outside-in tracking==

'''[[Oculus Rift|Rift]]''' (including [[Oculus Rift DK2|Rift development kit]])

'''[[PlayStation VR]]'''

==Tracking systems using outside-in tracking==

'''[[Constellation]]'''

'''[[PlayStation Camera]]'''

'''[[Neon Tracking System]]''' (used by [[HTC Link]]<ref>[http://www.roadtovr.com/htc-link-headset-ximmerse-neon-tracking-details/]]</ref>)

[[Category:Terms]] [[Category:Technical Terms]]

==References==

Outside-in tracking

2018-03-20T03:53:23Z

Cunningham: Deleting all reference to 'outside-in tracking' being the only technique. Even the Vive article disagrees.

{{stub}}
{{see also|Markerless outside-in tracking|Positional tracking}}
==Introduction==
[[File:Outside in tracking.png|thumb|Figure 1. Outside-in tracking (Image: www.wareable.com)]]
[[File:Inside out vs. outside in tracking.png|thumb|Figure 2. Inside-out vs. outside-in tracking (Image: Ishii, 2010)]]

Outside-in tracking is a form of [[positional tracking]] and, generally, it is a method of optical tracking. When referring to [[virtual reality]] (VR), tracking is the process of tracing the scene coordinates of moving objects in real-time, such as [[head-mounted display|head-mounted displays]] (HMDs) or motion controller peripherals. <ref name=”1”> Ribo, M., Pinz, A. and Fuhrmann, A.L. (2001). A new optical tracking system for virtual and augmented reality applications. Instrumentation and Measurement Technology Conference Proceedings</ref>

Outside-in VR tracking uses cameras or other sensors placed in a stationary location and oriented towards the tracked object (e.g. a headset) that moves freely around a designated area defined by the intersecting visual ranges of the cameras (Figure 1). The object is therefore observed from outside by the fixed tracking device. Usually, the tracked object has a known set of markers that are essential for the calculation of its position relative to the sensors. Also, while this type of positional tracking can be achieved using the visible light spectrum, it is common to use infra-red (IR) markers and cameras that can detect that type of light. <ref name=”1”></ref> <ref name=”2”> Mehling, M. (2006). Implementation of a Low Cost Marker Based Infrared Optical Tracking System. PhD thesis, Fachhochschule Stuttgart</ref> <ref name=”3”> Boger, Y. (2014). Positional tracking: "Outside-in" vs. "Inside-out.” Retrieved from http://vrguy.blogspot.pt/2014/08/positional-tracking-outside-in-vs.html</ref>

The majority of commercially available optical trackers use outside-in tracking. Its accuracy and performance are dependent on various factors like optical sensors, tracking markers and targets, processing power, and tracking algorithms, all of which can vary greatly. <ref name=”2”></ref> <ref name=”4”> Wang, J.F., Azuma, R., Bishop, G., Chi, V., Eyles, J. and Fuchs, H. (1990). Tracking a head-mounted display in a room-sized environment with head-mounted cameras. Proceedings of SPIE 1990 Technical Symposium on Optical Engineering and Photonics in Aerospace Sensing, Orlando, Florida</ref>

Outside-in tracking using markers is a well-developed and researched technology. Indeed, a group of researchers (Pustka et al., 2012) built a positional tracking system of this kind using only unmodified off-the-shelf mobile phones. Also, an early two-camera tracking system was described by Madritsch and Gervautz in 1996, and a system that used synchronized IR cameras, able to distinguish 6D targets, was described by Dorfmüller in 1999. <ref name=”5”> Pustka, D., Hülb, J.P., Willneff, J., Pankratz, F., Huber, M. and Klinker, G. (2012). Optical Outside-In Tracking using Unmodified Mobile Phones. IEEE International Symposium on Mixed and Augmented Reality</ref>

The outside-in tracking system needs room calibration after the cameras or sensors are placed, and the data acquired by the system is processed on a computer. <ref name=”3”></ref> <ref name=”5”></ref> Besides its application in VR, this type of tracking is used in motion capturing, as in the case of the film industry. <ref name=”2”></ref>

Outside-in tracking functions as the inverse of [[inside-out tracking]] (Figure 2). While the former places the sensors in a stationary location to track the VR goggle, in the latter the sensors are placed on the goggles and the markers in stationary locations. <ref name=”3”></ref> <ref name=”7”> Ishii, K. (2010). Augmented Reality: Fundamentals and nuclear related applications. Nuclear Safety and Simulation, 1(1)</ref>

==Devices using outside-in tracking==

'''[[Oculus Rift|Rift]]''' (including [[Oculus Rift DK2|Rift development kit]])

'''[[PlayStation VR]]'''

==Tracking systems using outside-in tracking==

'''[[Constellation]]'''

'''[[PlayStation Camera]]'''

'''[[Neon Tracking System]]''' (used by [[HTC Link]]<ref>[http://www.roadtovr.com/htc-link-headset-ximmerse-neon-tracking-details/]]</ref>)

[[Category:Terms]] [[Category:Technical Terms]]

==References==