Real-time Illumination and Visual Coherence for Photorealistic Augmented/Mixed Reality

A realistically inserted virtual object in the real-time physical environment is a desirable feature in augmented reality (AR) applications and mixed reality (MR) in general. This problem is considered a vital research area in computer graphics, a field that is experiencing ongoing discovery. The algorithms and methods used to obtain dynamic and real-time illumination measurement, estimating, and rendering of augmented reality scenes are utilized in many applications to achieve a realistic perception by humans. We cannot deny the powerful impact of the continuous development of computer vision and machine learning techniques accompanied by the original computer graphics and image processing methods to provide a significant range of novel AR/MR techniques. These techniques include methods for light source acquisition through image-based lighting or sampling, registering and estimating the lighting conditions, and composition of global illumination. In this review, we discussed the pipeline stages with the details elaborated about the methods and techniques that contributed to the development of providing a photo-realistic rendering, visual coherence, and interactive real-time illumination results in AR/MR

U-DiVE: Design and evaluation of a distributed photorealistic virtual reality environment

This dissertation presents a framework that allows low-cost devices to visualize and interact with photorealistic scenes. To accomplish this task, the framework makes use of Unity’s high-definition rendering pipeline, which has a proprietary Ray Tracing algorithm, and Unity’s streaming package, which allows an application to be streamed within its editor. The framework allows the composition of a realistic scene using a Ray Tracing algorithm, and a virtual reality camera with barrel shaders, to correct the lens distortion needed for the use on an inexpensive cardboard. It also includes a method to collect the mobile device’s spatial orientation through a web browser to control the user’s view, delivered via WebRTC. The proposed framework can produce low-latency, realistic and immersive environments to be accessed through low-cost HMDs and mobile devices. To evaluate the structure, this work includes the verification of the frame rate achieved by the server and mobile device, which should be higher than 30 FPS for a smooth experience. In addition, it discusses whether the overall quality of experience is acceptable by evaluating the delay of image delivery from the server up to the mobile device, in face of user’s movement. Our tests showed that the framework reaches a mean latency around 177 (ms) with household Wi-Fi equipment and a maximum latency variation of 77.9 (ms), among the 8 scenes tested.Esta dissertação apresenta um framework que permite que dispositivos de baixo custo visualizem e interajam com cenas fotorrealísticas. Para realizar essa tarefa, o framework faz uso do pipeline de renderização de alta definição do Unity, que tem um algoritmo de rastreamento de raio proprietário, e o pacote de streaming do Unity, que permite o streaming de um aplicativo em seu editor. O framework permite a composição de uma cena realista usando um algoritmo de Ray Tracing, e uma câmera de realidade virtual com shaders de barril, para corrigir a distorção da lente necessária para usar um cardboard de baixo custo. Inclui também um método para coletar a orientação espacial do dispositivo móvel por meio de um navegador Web para controlar a visão do usuário, entregue via WebRTC. O framework proposto pode produzir ambientes de baixa latência, realistas e imersivos para serem acessados por meio de HMDs e dispositivos móveis de baixo custo. Para avaliar a estrutura, este trabalho considera a verificação da taxa de quadros alcançada pelo servidor e pelo dispositivo móvel, que deve ser superior a 30 FPS para uma experiência fluida. Além disso, discute se a qualidade geral da experiência é aceitável, ao avaliar o atraso da entrega das imagens desde o servidor até o dispositivo móvel, em face da movimentação do usuário. Nossos testes mostraram que o framework atinge uma latência média em torno dos 177 (ms) com equipamentos wi-fi de uso doméstico e uma variação máxima das latências igual a 77.9 (ms), entre as 8 cenas testadas

Neural Radiance Fields: Past, Present, and Future

The various aspects like modeling and interpreting 3D environments and surroundings have enticed humans to progress their research in 3D Computer Vision, Computer Graphics, and Machine Learning. An attempt made by Mildenhall et al in their paper about NeRFs (Neural Radiance Fields) led to a boom in Computer Graphics, Robotics, Computer Vision, and the possible scope of High-Resolution Low Storage Augmented Reality and Virtual Reality-based 3D models have gained traction from res with more than 1000 preprints related to NeRFs published. This paper serves as a bridge for people starting to study these fields by building on the basics of Mathematics, Geometry, Computer Vision, and Computer Graphics to the difficulties encountered in Implicit Representations at the intersection of all these disciplines. This survey provides the history of rendering, Implicit Learning, and NeRFs, the progression of research on NeRFs, and the potential applications and implications of NeRFs in today's world. In doing so, this survey categorizes all the NeRF-related research in terms of the datasets used, objective functions, applications solved, and evaluation criteria for these applications.Comment: 413 pages, 9 figures, 277 citation

Content Format and Quality of Experience in Virtual Reality

In this paper, we investigate three forms of virtual reality content production and consumption. Namely, 360 stereoscopic video, the combination of a 3D environment with a video billboard for dynamic elements, and a full 3D rendered scene. On one hand, video based techniques facilitate the acquisition of content, but they can limit the experience of the user since the content is captured from a fixed point of view. On the other hand, 3D content allows for point of view translation, but real-time photorealistic rendering is not trivial and comes at high production and processing costs. We also compare the two extremes with an approach that combines dynamic video elements with a 3D virtual environment. We discuss the advantages and disadvantages of these systems, and present the result of a user study with 24 participants. In the study, we evaluated the quality of experience, including presence, simulation sickness and participants' assessment of content quality, of three versions of a cinematic segment with two actors. We found that, in this context, mixing video and 3D content produced the best experience.Comment: 25 page

Interactive Panorama VR360 for Corporate Communications: An Industrial Scenario Case Study

This case study explores interactive panorama implementation for corporate communications virtual reality 360 (VR360) application. Interactive panorama permits spherical panorama digital imagery being presented in three hundred sixty degrees visual experience instead of single angle limitation in conventional static image. The study proposes the use of interactive panorama as a corporate communications tool being considered from three experimental PEP aspects. The exploration of PEP framework seeks the suitability of implementing three key aspects of people, equipment and product for interactive panorama virtual reality 360 experience. With the developing advances of interactive panorama, it has been introduced by online social media providers as essential feature which allows individual and corporate users to post 360 content. This case study takes advantage on the actual on-going marketing experience and technical insight of a participating case company and several industrial scenario use cases. In this paper we describe interactive panorama content creation, PEP framework, a user study and directions for future work