Virtual Reality (VR) technology has the potential to support knowledge communication in several sectors. Still, when educators make use of immersive VR technology in favor of presenting their knowledge, their audience within the same room may not be able to see them any more due to wearing head-mounted displays (HMDs). In this paper, we propose the Avatar2Avatar system and design, which augments the visual aspect during such a knowledge presentation. Avatar2Avatar enables users to see both a realistic representation of their respective counterpart and the virtual environment at the same time. We point out several design aspects of such a system and address design challenges and possibilities that arose during implementation. We specifically explore opportunities of a system design for integrating 2D video-avatars in existing roomscale VR setups. An additional user study indicates a positive impact concerning spatial presence when using Avatar2Avatar.

Representing users within an immersive virtual environment is an essential functionality of a multi-person virtual reality system. Especially when communicative or collaborative tasks must be performed, there exist challenges about realistic embodying and integrating such avatar representations. A shared comprehension of local space and non-verbal communication (like gesture, posture or self-expressive cues) can support these tasks. In this paper, we introduce a novel approach to create realistic, video-texture based avatars of co-located users in real-time and integrate them in an immersive virtual environment. We show a straight forward and low-cost hard- and software solution to do so. We discuss technical design problems that arose during implementation and present a qualitative analysis on the usability of the concept from a user study, applying it to a training scenario in the automotive sector.

WebGL enabled real-time 3D graphics on the Web. With the objective to integrate 3D graphics into the rest of the Web technology stack, and to make it easier for Web developers to develop interactive 3D graphics, Declarative 3D approaches were developed: X3DOM and XML3D. While the former focuses on backward-compatibility to X3D and a large set of convenience elements, the latter attempts to define a minimal set of flexible elements as an extension to HTML5. It has now been more than 6 years since Declarative 3D was first proposed for the Web. However, despite their different philosophies neither X3DOM nor XML3D has yet been able to achieve the same momentum and adoption rate as imperative frameworks like three.js. In the meantime, the underlying Web technology stack has made significant advances. In this paper we revisit both approaches in light of new Web technologies, such as Web Components, to define a small set of core elements that can provide the convenience of X3DOM while remaining as flexible and customizable as XML3D. Further, we present a strategy for building upon these core elements to enable user-defined elements, with the ability to cover domain-specific needs in Declarative 3D. Lastly, we show how these concepts can be used to simplify existing approaches (i.e. X3DOM and XML3D) and provide the basic building blocks of Declarative 3D on the Web.

Declarative 3D (Dec3D) implementations, most notably XML3D and X3DOM, have enabled a seamless integration of 3D and 2D content on the same web page. Yet one of the major web technologies, Cascading Style Sheets (CSS), has not been integrated. The usage of CSS for 3D content has always been envisaged but never fully approached, because only polyfills for declarative 3D implementations exist and only recent developments have made custom CSS properties available. In this paper we will present a deep integration and adaption of CSS for Dec3D content and, hence, provide the final component necessary to fully integrate 3D content into the web technology stack. Our integration model allows for appearance definitions, such as visibility and materials, at a novel level of expressiveness. CSS-Selectors, inheritance, as well as media types provide unique means to change a scene's final appearance in a flexible and powerful way. Using CSS, it is possible to define the appearance of a 3D object dependent on the DOM hierarchy position or the screen resolution and orientation without a single line of JavaScript. The integration of CSS further enables the use of browser debugging facilities that have not been usable before. Because the requirements of 3D content are different compared to those of 2D content, we will point out existing limitations and necessary future additions to improve the interoperability of CSS with 3D content.

Graphics hardware has become ubiquitous: Integrated into CPUs and into mobile devices and recently even embedded into cars. With the advent of WebGL, accelerated graphics is finally accessible from within the web browser. However, still the capabilities of GPUs are almost exclusively exploited by the video game industry, where experts produce specialized content for game engines.

Recent advances in Web technology, especially real-time 3D content using WebGL, require an efficient way to transfer binary data. Images, audio and video have respective HTML tags and accompanying data formats that transparently handle binary transmission and decompression. 3D data, on the other hand, has to be handled explicitly by the client application. In contrast to images, audio and video, 3D data is inhomogeneous and neither common formats nor compression algorithms have been established for the Web. Despite the many existing formats for binary transmission of 3D data none has been able to provide a general binary format for all kinds of 3D data including meshes, textures, animations, and materials. Existing formats are domain-specific and fixed on a certain set of input data and thus too specific to handle other types of data. Blast is a general container format for structured binary transmission on the Web that can be used for all types of 3D scene data. Instead of defining a fixed set of encodings and compression algorithms Blast exploits the code on demand paradigm to provide a simple yet powerful encoder-agnostic basis to leverage existing domain-specific solutions and compression techniques. Because streaming is of primary importance for a good user experience Blast is designed on the basis of self-contained chunks to enable JavaScript clients to utilize Web Workers for parallel decoding and to provide early feedback to the user.

In computer graphics a material is a visual concept that is parameterizable and should work for arbitrary 3D assets and rendering systems. Since provided parameters and attributes as well as the capabilities of rendering systems vary considerably, a material needs to adapt to its execution environment. In current approaches, the adaptation logic is 'baked' into the rendering application based on string manipulation, compiler directives, or metaprogramming facilities. However, in order to achieve application-independent and self-contained material descriptions, the adaptation logic needs to be part of the material description itself.

The current market situation demands manufacturers increase the flexibility, adaptability and efficiency of their production processes, from product design to manufacturing, and taking the entire product lifecycle into consideration. Digital Factories present a vision of future manufacturing in which digital continuity through production processes facilitates these requirements. This paper investigates how Future Internet technology may be applied and extended in order to fulfil the requirements of Digital Factories and contribute in a significant way to this paradigm shift in manufacturing. The authors present two Digital Factories use cases from which they derive requirements towards a proposed Future Internet Digital Factories architecture. A discussion of the results and an outlook to future work conclude the paper.