Zhou et al (2008, p.193) observe that the difference between tracking techniques in Augmented Reality (AR) and those used in Virtual Reality (VR) stem from the interoperability of the two systems. On the other hand, State et al (1995, p.1) contend that there are significant contributions to tracking in VR than AR. Work prior to that of State et al (1995) indicates that the better fraction of tracking systems in VR are magnetic. However, Zhou et al (2008, p.196) observe that significant developments on tracking in AR are either vision-based, sensor-based or hybrid techniques. Bostanci et al (2011, p.425) classify the AR tracking methods in four major categories comprising of indoor, outdoor, fusion and recent approaches.
The tracking techniques for VR and AR on the indoor platform are related in the sense that they both use markers that emit signals such as the magnetic and light active markers (Bostanci et al, 2011, p.425; State et al, 1995, p.1). Berre et al (2006, p.5) confirm the argument by stating that one of the most usually applied orientation and track position in AR is the use of magnetic sensor like the Polhemus Isotrac. Moreover, Joele (2005, p.15) offers that tracking in AR involves a set of stern requisites one of them being the high six Degree of Freedom (DOF) when it comes to spatial accuracy in orientation and position. Wagner and Schmalstieg (2009, p.193), while researching on the AR tracking in mobile phones argue that both AR and VR need 6-DOF pose devices’ tracking. These devices include tangible interface objects for AR and head-mounted displays (HMD) for VR. Additionally, Neumann and Cho (1996, p.111) and Zhou et al (2008, p.193) argue that every tracking system contains a device that has the capability to generate a signal that is detectable by a sensor despite the tracking technique involved in AR or VR.
Concerning HMDs, Azuma (1997, p.2) observes the excessive association of AR with the usage of HMDs. In disambiguating this association, Azuma (1997, p.2) offers that AR does not include 2-D overlays or film. Additionally, Azuma, 1997, p.12) argues that monitor-based configurations are used in AR as opposed to HMDs. In the event of mobile case tracking, the user does not wear the HMD since cameras might relocate while attached to a robot and have their locations tracked instead. On the other hand, VR tracking techniques require the user to wear the HMD in order for effective tracking to occur.
Wagner and Schmalstieg (2009, p.1) argue that AR tracking requires cameras only of higher quality than those used in VR. Bottom line, therefore, both VR and AR make use of camera technology for tracking. Additionally, Bostanci et al (2011, p.425-6) that while AR can incorporate visual tracking for both indoor and outdoor tracking techniques, the VR visual tracking can only function in the indoor environment. Zhou et al (2008, p.195) imply that while AR employs both indoor and outdoor tracking techniques, VR can only do so in the...