Illuminating the mixed reality stage: applying complex lighting conditions to AR

Author(s):  
M. Wittkamper ◽  
E. Meier ◽  
W. Broll
2021 ◽  
Author(s):  
Lohit Petikam

<p>Art direction is crucial for films and games to maintain a cohesive visual style. This involves carefully controlling visual elements like lighting and colour to unify the director's vision of a story. With today's computer graphics (CG) technology 3D animated films and games have become increasingly photorealistic. Unfortunately, art direction using CG tools remains laborious. Since realistic lighting can go against artistic intentions, art direction is almost impossible to preserve in real-time and interactive applications. New live applications like augmented and mixed reality (AR and MR) now demand automatically art-directed compositing in unpredictably changing real-world lighting. </p> <p>This thesis addresses the problem of dynamically art-directed 3D composition into real scenes. Realism is a basic component of art direction, so we begin by optimising scene geometry capture in realistic composites. We find low perceptual thresholds to retain perceived seamlessness with respect to optimised real-scene fidelity. We then propose new techniques for automatically preserving art-directed appearance and shading for virtual 3D characters. Our methods allow artists to specify their intended appearance for different lighting conditions. Unlike with previous work, artists can direct and animate stylistic edits to automatically adapt to changing real-world environments. We achieve this with a new framework for look development and art direction using a novel latent space of varied lighting conditions. For more dynamic stylised lighting, we also propose a new framework for art-directing stylised shadows using novel parametric shadow editing primitives. This is a first approach that preserves art direction and stylisation under varied lighting in AR/MR.</p>


2009 ◽  
Vol 8 (2) ◽  
pp. 13-18
Author(s):  
William Russell Pensyl ◽  
Tran C. T. Qui ◽  
Pei Fang Hsin ◽  
Shang Ping Lee ◽  
Daniel K. Jernigan

We have developed a system which enables us to track participant-observers accurately in a large area for the purpose of immersing them in a mixed reality environment. This system is robust even under uncompromising lighting conditions. Accurate tracking of the observer�s spatial and orientation point of view is achieved by using hybrid inertial sensors and computer vision techniques. We demonstrate our results by presenting a life-size, animated human avatar sitting in a real chair, in a stable and low-jitter manner. The system installation allows the observers to freely walk around and navigate themselves in the environment even while still being able to see the avatar from various angles. The project installation provides an exciting way for cultural and historical narratives to be presented vividly in the real present world.


2021 ◽  
Author(s):  
Lohit Petikam

<p>Art direction is crucial for films and games to maintain a cohesive visual style. This involves carefully controlling visual elements like lighting and colour to unify the director's vision of a story. With today's computer graphics (CG) technology 3D animated films and games have become increasingly photorealistic. Unfortunately, art direction using CG tools remains laborious. Since realistic lighting can go against artistic intentions, art direction is almost impossible to preserve in real-time and interactive applications. New live applications like augmented and mixed reality (AR and MR) now demand automatically art-directed compositing in unpredictably changing real-world lighting. </p> <p>This thesis addresses the problem of dynamically art-directed 3D composition into real scenes. Realism is a basic component of art direction, so we begin by optimising scene geometry capture in realistic composites. We find low perceptual thresholds to retain perceived seamlessness with respect to optimised real-scene fidelity. We then propose new techniques for automatically preserving art-directed appearance and shading for virtual 3D characters. Our methods allow artists to specify their intended appearance for different lighting conditions. Unlike with previous work, artists can direct and animate stylistic edits to automatically adapt to changing real-world environments. We achieve this with a new framework for look development and art direction using a novel latent space of varied lighting conditions. For more dynamic stylised lighting, we also propose a new framework for art-directing stylised shadows using novel parametric shadow editing primitives. This is a first approach that preserves art direction and stylisation under varied lighting in AR/MR.</p>


2020 ◽  
Vol 2020 (11) ◽  
pp. 128-1-128-7
Author(s):  
Jesús Gutiérrez ◽  
Toinon Vigier ◽  
Patrick Le Callet

This paper presents a study on Quality of Experience (QoE) evaluation of 3D objects in Mixed Reality (MR) scenarios. In particular, a subjective test was performed with Microsoft HoloLens, considering different degradations affecting the geometry and texture of the content. Apart from the analysis of the perceptual effects of these artifacts, given the need for recommendations for subjective assessment of immersive media, this study was also aimed at: 1) checking the appropriateness of a single stimulus methodology (ACR-HR) for these scenarios where observers have less references than with traditional media, and 2) analyzing the possible impact of environment lighting conditions on the quality evaluation of 3D objects in mixed reality (MR), and 3) benchmark state-of-the-art objective metrics in this context. The subjective results provide insights for recommendations for subjective testing in MR/AR, showing that ACR-HR can be used in similar QoE tests and reflecting the influence among the lighting conditions, the content characteristics, and the type of degradations. The objective results show an acceptable performance of perceptual metrics for geometry quantization artifacts and point out the need of further research on metrics covering both geometry and texture compression degradations.


2021 ◽  
pp. 1-18
Author(s):  
Maxim Igorevich Sorokin ◽  
Dmitry Dmitrievich Zhdanov ◽  
Ildar Vagizovich Valiev

The paper examines the causes of visual discomfort in mixed reality systems and algorithmic solutions that eliminate one of the main causes of discomfort, namely, the mismatch between the lighting conditions of objects in the real and virtual worlds. To eliminate this cause of discomfort, the algorithm is proposed, which consists in constructing groups of shadow rays from points on the boundaries of shadows to points on the boundaries of objects. Part of the rays corresponding to the real lighting conditions form caustics in area of the real light source, which makes it possible to determine the source of illumination of virtual objects for their correct embedding into the mixed reality system. Convolutional neural networks and computer vision algorithms were used to classify shadows in the image. Examples of reconstructing the coordinates of a light source from RGBD data are presented.


2021 ◽  
pp. 1-17
Author(s):  
Andrew Fedorovich Lemeshev ◽  
Dmitry Dmitrievich Zhdanov ◽  
Boris Khaimovich Barladyan

The paper deals with the problem of visual perception discomfort inherent in mixed reality systems, more precisely, the determination of the lighting parameters of the objects of the virtual world, corresponding to the lighting conditions of the real world, into which the virtual objects are embedded. The paper proposes an effective solution to the problem of reconstructing the coordinates of a light source from an RGBD image of the real world. A detailed description of the algorithm and the results of a numerical experiment on reconstructing the coordinates of light sources in a model scene are given. The accuracy of coordinate recovery is analyzed and the limitations of the method are considered, associated with the inaccuracy of determining the boundaries of objects and their shadows, as well as the lack of interconnected areas of the boundaries of objects and their shadows in the RGBD image of the scene.


Author(s):  
Jacqueline A. Towson ◽  
Matthew S. Taylor ◽  
Diana L. Abarca ◽  
Claire Donehower Paul ◽  
Faith Ezekiel-Wilder

Purpose Communication between allied health professionals, teachers, and family members is a critical skill when addressing and providing for the individual needs of patients. Graduate students in speech-language pathology programs often have limited opportunities to practice these skills prior to or during externship placements. The purpose of this study was to research a mixed reality simulator as a viable option for speech-language pathology graduate students to practice interprofessional communication (IPC) skills delivering diagnostic information to different stakeholders compared to traditional role-play scenarios. Method Eighty graduate students ( N = 80) completing their third semester in one speech-language pathology program were randomly assigned to one of four conditions: mixed-reality simulation with and without coaching or role play with and without coaching. Data were collected on students' self-efficacy, IPC skills pre- and postintervention, and perceptions of the intervention. Results The students in the two coaching groups scored significantly higher than the students in the noncoaching groups on observed IPC skills. There were no significant differences in students' self-efficacy. Students' responses on social validity measures showed both interventions, including coaching, were acceptable and feasible. Conclusions Findings indicated that coaching paired with either mixed-reality simulation or role play are viable methods to target improvement of IPC skills for graduate students in speech-language pathology. These findings are particularly relevant given the recent approval for students to obtain clinical hours in simulated environments.


2019 ◽  
pp. 22-27
Author(s):  
Cenk Yavuz ◽  
Ceyda Aksoy Tırmıkç ◽  
Burcu Çarklı Yavuz

Today the number of office workers has reached to an enormous number due to the fast-growing technology. Most of these office workers spend long hours in enclosed spaces with little/no daylight penetration. The lack of daylight causes physiological and psychological problems with the workers. At this point lighting systems become prominent as the source and the solution of the problem. Photometric flicker event which arises in the lighting systems can sometimes become visible and brings a lot of issues with it. In this paper, an experimental work has been done to investigate the effect of flicker. For this purpose, the flicker values of 3 different experiment rooms for different lighting conditions and scenarios have been measured and a questionnaire study has been carried out in the experiment rooms with 30 participants. In conclusion, the effect of the flicker event on the volunteers have been classified and some methods have been proposed not to experience flicker effects.


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