SARA: A Microservice-Based Architecture for Cross-Platform Collaborative Augmented Reality

Abstract

Augmented Reality (AR) functionalities may be effectively leveraged in collaborative service scenarios (e.g., remote maintenance, on-site building, street gaming, etc.). Standard development cycles for collaborative AR require to code for each specific visualization platform and implement the necessary control mechanisms over the shared assets. in order to face this challenge, this paper describes SARA, an architecture to support cross-platform collaborative Augmented Reality applications based on microservices. The architecture is designed to work over the concept of collaboration models which regulate the interaction and permissions of each user over the AR assets. Five of these collaboration models were initially integrated in SARA (turn, layer, ownership, hierarchy-based and unconstrained examples) and the platform enables the definition of new ones. Thanks to the reusability of its components, during the development of an application, SARA enables focusing on the application logic while avoiding the implementation of the communication protocol, data model handling and orchestration between the different, possibly heterogeneous, devices involved in the collaboration (i.e., mobile or wearable AR devices using different operating systems). to describe how to build an application based on SARA, a prototype for HoloLens and iOS devices has been implemented. the prototype is a collaborative voxel-based game in which several players work real time together on a piece of land, adding or eliminating cubes in a collaborative manner to create buildings and landscapes. Turn-based and unconstrained collaboration models are applied to regulate the interaction. the development workflow for this case study shows how the architecture serves as a framework to support the deployment of collaborative AR services, enabling the reuse of collaboration model components, agnostically handling client technologies.Appl. Sci. 2020, 10, 2074 2 of 26 wearable ones). SARA is also able to automatically orchestrate the rules for the collaboration policy needed for the target application. To do so, we defined a set of collaboration models which implement the most frequent collaboration strategies, such as turn-based, layer-based and hierarchy-based ones. Finally, the architecture facilitates the adaptation of non-collaborative applications to make them collaborative, and even to turn those non-AR applications into AR ones. SARA architecture is tested in this paper through a case-based methodology-technology empirical evaluation-to complete a proof-of-concept validation. The case under study is the development of a voxel-based collaborative game, which is implemented to demonstrate the development life-cycle and the management of unconstrained and turn-based collaboration models.This paper is structured as follows. First, in Section 2 we provide an overview of the current state of the art regarding AR collaborative systems as well as collaborative Augmented Reality architectures. In Section 3 we present an analysis of the collaboration over A...

Review of Microsoft HoloLens Applications over the Past Five Years

“…Based on these functions, various studies have been conducted to determine methods for using HoloLens more efficiently. For instance, a study on effectively controlling the HoloLens, using the gaze, gesture and voice control functions provided by the device, and studies on methods for utilizing this device in various industrial fields have been conducted [7][8][9][10][11][12][13][14][15][16][17]. Research on methods of visualizing the scanned image or data of an actual object as 3D contents [18][19][20] and correcting them [21,22] have also been conducted.…”