ARK: augmented reality kiosk

This paper aims at presenting a very first prototype of an Augmented Reality (AR) system that as been developed in recent months at our research group. The prototype adopts a kiosk format and allows users to directly interact with an AR environment using a conventional data glove. The most relevant feature of this environment is the use of a common monitor to display AR images, instead of employing specific Head-Mounted Displays. By integrating a half-silvered mirror and a black virtual hand, our solution solves the occlusion problem that normally occurs when a user interacts with a virtual environment displayed by a monitor or other projection system

ARK multi-user

This paper presents a monitor-based prototype for the visualisation and interaction of an Augmented Reality (AR) system, which recently developed at CCG and demonstrated during the SIACG2002 conference held in Guimarães, Portugal. ARK – Augmented Reality Kiosk - is a set-up based on the prototypes developed in the European Virtual Showcases project to which direct interaction has been added. A normal monitor and a half-silvered mirror constitute the usual set-up for the kiosk. By integrating a half-silvered mirror and a black virtual hand, the CCG solution solves the occlusion problem that normally occurs when a user interacts with a virtual environment displayed by a monitor or other projection system. Conceived with limited monetary resources this portable solution can be deployed in different application contexts as, for instance, culture heritage. This paper presents an extension of the solution to a multi-user platform for a Portuguese museum

Real-Time Occlusion Handling in Augmented Reality Based on an Object Tracking Approach

To produce a realistic augmentation in Augmented Reality, the correct relative positions of real objects and virtual objects are very important. In this paper, we propose a novel real-time occlusion handling method based on an object tracking approach. Our method is divided into three steps: selection of the occluding object, object tracking and occlusion handling. The user selects the occluding object using an interactive segmentation method. The contour of the selected object is then tracked in the subsequent frames in real-time. In the occlusion handling step, all the pixels on the tracked object are redrawn on the unprocessed augmented image to produce a new synthesized image in which the relative position between the real and virtual object is correct. The proposed method has several advantages. First, it is robust and stable, since it remains effective when the camera is moved through large changes of viewing angles and volumes or when the object and the background have similar colors. Second, it is fast, since the real object can be tracked in real-time. Last, a smoothing technique provides seamless merging between the augmented and virtual object. Several experiments are provided to validate the performance of the proposed method

Réalité augmentée à partir d'une séquence vidéo en utilisant la stéréoscopie dense.

International audienceCet article s'intéresse à la réalité augmentée, c'est à dire à l'intégration d'objets virtuels générés par ordinateur dans une séquence d'images en gérant les occultations. L'occultation est l'un des problèmes cruciaux en réalité augmentée. Il consiste à tenir compte des interactions entre les éléments virtuels insérés et la scène réelle: les parties occultées de ces éléments doivent être déterminées. La méthode proposée repose sur le calcul des cartes de disparité en utilisant les techniques de mise en correspondance denses. Afin de retrouver des cartes de disparité denses, nous présentons dans cet article deux techniques d'appariement. La première est basée sur la programmation dynamique. Bien que cette méthode donne des résultats satisfaisants, elle reste néanmoins très gourmande en temps de calcul. Afin améliorer le temps de calcul ainsi que la qualité des résultats, nous proposons une autre méthode dite hybride basée sur l'approche multi résolution et la programmation dynamique. Les cartes de disparité ainsi obtenues sont appliqués en réalité augmentée afin d'intégrer de manière réaliste des objets virtuels générées par ordinateur dans une séquence d'images. La méthode d'augmentation proposée réduit considérablement l'intervention de l'utilisateur. L'applicabilité de la méthode est démontrée sur de nombreuses séquences d'images

Virtual Occlusions Through Implicit Depth

For augmented reality (AR), it is important that virtual assets appear to 'sit among' real world objects. The virtual element should variously occlude and be occluded by real matter, based on a plausible depth ordering. This occlusion should be consistent over time as the viewer's camera moves. Unfortunately, small mistakes in the estimated scene depth can ruin the downstream occlusion mask, and thereby the AR illusion. Especially in real-time settings, depths inferred near boundaries or across time can be inconsistent. In this paper, we challenge the need for depth-regression as an intermediate step. We instead propose an implicit model for depth and use that to predict the occlusion mask directly. The inputs to our network are one or more color images, plus the known depths of any virtual geometry. We show how our occlusion predictions are more accurate and more temporally stable than predictions derived from traditional depth-estimation models. We obtain state-of-the-art occlusion results on the challenging ScanNetv2 dataset and superior qualitative results on real scenes

Overcoming the limitations of commodity augmented reality head mounted displays for use in product assembly

Numerous studies have shown the effectiveness of utilizing Augmented Reality (AR) to deliver work instructions for complex assemblies. Traditionally, this research has been performed using hand-held displays, such as smartphones and tablets, or custom-built Head Mounted Displays (HMDs). AR HMDs have been shown to be especially effective for assembly tasks as they allow the user to remain hands-free while receiving work instructions. Furthermore, in recent years a wave of commodity AR HMDs have come to market including the Microsoft HoloLens, Magic Leap One, Meta 2, and DAQRI Smart Glasses. These devices present a unique opportunity for delivering assembly instructions due to their relatively low cost and accessibility compared to custom built AR HMD solutions of the past. Despite these benefits, the technology behind these HMDs still contains many limitations including input, user interface, spatial registration, navigation and occlusion. To accurately deliver work instructions for complex assemblies, the hardware limitations of these commodity AR HMDs must be overcome. For this research, an AR assembly application was developed for the Microsoft HoloLens using methods specifically designed to address the aforementioned issues. Input and user interface methods were implemented and analyzed to maximize the usability of the application. An intuitive navigation system was developed to guide users through a large training environment, leading them to the current point of interest. The native tracking system of the HoloLens was augmented with image target tracking capabilities to stabilize virtual content, enhance accuracy, and account for spatial drift. This fusion of marker-based and marker-less tracking techniques provides a novel approach to display robust AR assembly instructions on a commodity AR HMD. Furthermore, utilizing this novel spatial registration approach, the position of real-world objects was accurately registered to properly occlude virtual work instructions. To render the desired effect, specialized computer graphics methods and custom shaders were developed and implemented for an AR assembly application. After developing novel methods to display work instructions on a commodity AR HMD, it was necessary to validate that these work instructions were being accurately delivered. Utilizing the sensors on the HoloLens, data was collected during the assembly process regarding head position, orientation, assembly step times, and an estimation of spatial drift. With the addition of wearable physiological sensor data, this data was fused together in a visualization application to validate instructions were properly delivered and provide an opportunity for an analysist to examine trends within an assembly session. Additionally, the spatial drift data was then analyzed to gain a better understanding of how spatial drift accumulates over time and ensure that the spatial registration mitigation techniques was effective. Academic research has shown that AR may substantial reduce cost for assembly operations through a reduction in errors, time, and cognitive workload. This research provides novel solutions to overcome the limitations of commodity AR HMDs and validate their use for product assembly. Furthermore, the research provided in this thesis demonstrates the potential of commodity AR HMDs and how their limitations can be mitigated for use in product assembly tasks

Augmented Reality Markerless Multi-Image Outdoor Tracking System for the Historical Buildings on Parliament Hill

[EN] Augmented Reality (AR) applications have experienced extraordinary growth recently, evolving into a well-established method for the dissemination and communication of content related to cultural heritage¿including education. AR applications have been used in museums and gallery exhibitions and virtual reconstructions of historic interiors. However, the circumstances of an outdoor environment can be problematic. This paper presents a methodology to develop immersive AR applications based on the recognition of outdoor buildings. To demonstrate this methodology, a case study focused on the Parliament Buildings National Historic Site in Ottawa, Canada has been conducted. The site is currently undergoing a multiyear rehabilitation program that will make access to parts of this national monument inaccessible to the public. AR experiences, including simulated photo merging of historic and present content, are proposed as one tool that can enrich the Parliament Hill visit during the rehabilitation. Outdoor AR experiences are limited by factors, such as variable lighting (and shadows) conditions, caused by changes in the environment (objects height and orientation, obstructions, occlusions), the weather, and the time of day. This paper proposes a workflow to solve some of these issues from a multi-image tracking approach.This work has been developed under the framework of the New Paradigms/New Tools for Heritage Conservation in Canada, a project funded through the Social Sciences and Humanities Research Council of Canada (SSHRC).Blanco-Pons, S.; Carrión-Ruiz, B.; Duong, M.; Chartrand, J.; Fai, S.; Lerma, JL. (2019). Augmented Reality Markerless Multi-Image Outdoor Tracking System for the Historical Buildings on Parliament Hill. 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Designing and implementing interactive and realistic augmented reality experiences

In this paper, we propose an approach for supporting the design and implementation of interactive and realistic Augmented Reality (AR). Despite the advances in AR technology, most software applications still fail to support AR experiences where virtual objects appear as merged into the real setting. To alleviate this situation, we propose to combine the use of model-based AR techniques with the advantages of current game engines to develop AR scenes in which the virtual objects collide, are occluded, project shadows and, in general, are integrated into the augmented environment more realistically. To evaluate the feasibility of the proposed approach, we extended an existing game platform named GREP to enhance it with AR capacities. The realism of the AR experiences produced with the software was assessed in an event in which more than 100 people played two AR games simultaneously.This work is supported by the project CREAx and PACE funded by the Spanish Ministry of Economy, Industry and Competitiveness (TIN2014-56534-R and TIN2016-77690-R)

Взаємодія моделей з реальними об’єктами як спосіб удосконалення доповненої реальності

Unlike a purely virtual world, it is much more difficult for the user to believe in the reality of augmented reality objects. Due to the lack of proper lighting or shadows, the object may appear to be floating in the air, detached from the real objects around it. One obvious problem with augmented reality is that a virtual object appears remote from the real object, but it still appears in front of it. An approach is proposed that will allow the interaction of real and virtual objects. Both real and virtual objects can be moved and rotated in the scene, preserving overlaps. A virtual object can also be placed in front of or behind a real object relative to the camera, which decides whether or not to overlap. The proposed algorithm consists of five stages and the system architecture. The evaluation is based on five defined criteria. Results and ways of improvement for the future research are presented