On the precision of third person perspective augmented reality for target designation tasks

Abstract

The availability of powerful consumer-level smart devices and off-the-shelf software frameworks has tremendously popularized augmented reality (AR) applications. However, since the built-in cameras typically have rather limited field of view, it is usually preferable to position AR tools built upon these devices at a distance when large objects need to be tracked for augmentation. This arrangement makes it difficult or even impossible to physically interact with the augmented object. One solution is to adopt third person perspective (TPP) with which the smart device shows in real time the object to be interacted with, the AR information and the user herself, all captured by a remote camera. Through mental transformation between the user-centric coordinate space and the coordinate system of the remote camera, the user can directly interact with objects in the real world. To evaluate user performance under this cognitively demanding situation, we developed such an experimental TPP AR system and conducted experiments which required subjects to make markings on a whiteboard according to virtual marks displayed by the AR system. The same markings were also made manually with a ruler. We measured the precision of the markings as well as the time to accomplish the task. Our results show that although the AR approach was on average around half a centimeter less precise than the manual measurement, it was approximately three times as fast as the manual counterpart. Additionally, we also found that subjects could quickly adapt to the mental transformation between the two coordinate systems.

What Can I Do There? Controlling AR Self-Avatars to Better Perceive Affordances of the Real World

“…In MR, Salamin et al [31] showed that moving the user's viewpoint behind their bodies reduced the training required for a ball-catching task. Liu et al [17] also showed that the 3PP resulted in slightly less precision during a measurement task in AR, but it allowed being three times faster. In VR, the effects of the 3PP are contrasting.…”

Evaluation of Augmented Reality-Based Building Diagnostics Using Third Person Perspective

“…The overall system design is similar to the one presented in our previous work on indoor TPP AR experiments [41]. In terms of hardware (see Figure 3), we offloaded the video augmentation operation onto a desktop computer, HP Z600 workstation (HP Inc., Palo Alto, CA, USA), for improved system performance.…”

“…A Logitech C920 HD Pro webcam (Logitech International S.A., Lausanne, Switzerland) was attached to the computer for video capture. A frequent comment we received from user experiments in [41] was that the screen of the smartphone was too small so it was difficult to discern the virtual targets. Therefore, in this implementation, the augmented video was sent to a tablet computer, Google Nexus 9 (Google LLC, Mountain View, CA, USA), featuring an 8.9 inch display at the resolution of 2048 × 1536.…”

“…As for the buttons, we have the "Start" button for connecting to or disconnecting from the desktop computer, the "Previous" and the "Next," buttons for users to scroll through all the IR targets during the experiments. Users can also zoom in or out on the video through pinching, a most requested interaction from [41]. The 13 pre-warped IR images were imported into Unity and composited with the video through customized OpenGL shaders at the rate of 24 frames per second.…”