Changes

{{see also|MarkerMarkerless inside-less, Inside-Out Tracking‎out 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 QR codes 2-dimensional barcodes as [[fiducial markers]].]]In [[File:Acer mixed reality headset inside-out.png|thumb|Figure 3. Inside-out tracking]], the tracking camera is placed on the [[device]] being tracked such as an [[HMD]](image: www. The device looks out to the world around it and uses the changing perspectives of the outside world to determine its own position in spacewareable. [[Fiducial markerscom)]] such as QR codes can be placed in the outside world to serve as reference points for the tracking camera.

The opposite of inside==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-in 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>

==Devices 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 [[HTC Vivemarkerless 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>

==Tracking systems 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 trackingwill be affected. <ref name=”2”></ref> <ref name=[[Lighthouse]]”3”></ref> <ref name=”5”> Mehling, M. (2006). Implementation of a Low Cost Marker Based Infrared Optical Tracking System. PhD thesis, Fachhochschule Stuttgart</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]]''' '''[[Oculus Quest]]''' <ref name=”7”> AR/VR Tips (2020). VR Headset Comparison. Retrieved from https://arvrtips.com/vr-headset-comparison-tool/</ref> '''[[Oculus Rift St]]''' '''[[HP Reverb G1 & G2]]''' ==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)''' '''NMERSO''' [[Category:Terms]] [[Category:Technical Terms]] ==References==