Ubiquitous volume rendering in the web platform

176 p.The main thesis hypothesis is that ubiquitous volume rendering can be achieved using WebGL. The thesis enumerates the challenges that should be met to achieve that goal. The results allow web content developers the integration of interactive volume rendering within standard HTML5 web pages. Content developers only need to declare the X3D nodes that provide the rendering characteristics they desire. In contrast to the systems that provide specific GPU programs, the presented architecture creates automatically the GPU code required by the WebGL graphics pipeline. This code is generated directly from the X3D nodes declared in the virtual scene. Therefore, content developers do not need to know about the GPU.The thesis extends previous research on web compatible volume data structures for WebGL, ray-casting hybrid surface and volumetric rendering, progressive volume rendering and some specific problems related to the visualization of medical datasets. Finally, the thesis contributes to the X3D standard with some proposals to extend and improve the volume rendering component. The proposals are in an advance stage towards their acceptance by the Web3D Consortium

Real-time volume rendering and tractography visualization on the web

In the field of computer graphics, Volume Rendering techniques allow the visualization of 3D datasets, and specifically, Volume Ray-Casting renders images from volumetric datasets, typically used in some scientific areas, such as medical imaging -- This article aims to describe the development of a combined visualization of tractography and volume rendering of brain T1 MRI images in an integrated way -- An innovative web viewer for interactive visualization of neuro-imaging data has been developed based on WebGL -- This recently developed standard enables the clients to use the web viewer on a wide range of devices, with the only requirement of a compliant web-browser -- As the majority of the rendering tasks take place in the client machine, the effect of bottlenecks and server overloading are minimized -- The web application presented is able to compete with desktop tools, even supporting high graphical demands and facing challenges regarding performance and scalability -- The developed software modules are available as open source code and include MRI volume data and tractography generated by the Diffusion Toolkit, and connectivity data from the Connectome Mapping Toolkit -- Our contribution for the Volume Web Viewer implements early ray termination step according to the tractography depthmap, combining volume images and estimated white matter fibers -- Furthermore, the depthmap system extension can be used for visualization of other types of data, where geometric and volume elements are displayed simultaneousl

Developing serious games for cultural heritage: a state-of-the-art review

Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result, the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented

Serious Games in Cultural Heritage

Although the widespread use of gaming for leisure purposes has been well documented, the use of games to support cultural heritage purposes, such as historical teaching and learning, or for enhancing museum visits, has been less well considered. The state-of-the-art in serious game technology is identical to that of the state-of-the-art in entertainment games technology. As a result the field of serious heritage games concerns itself with recent advances in computer games, real-time computer graphics, virtual and augmented reality and artificial intelligence. On the other hand, the main strengths of serious gaming applications may be generalised as being in the areas of communication, visual expression of information, collaboration mechanisms, interactivity and entertainment. In this report, we will focus on the state-of-the-art with respect to the theories, methods and technologies used in serious heritage games. We provide an overview of existing literature of relevance to the domain, discuss the strengths and weaknesses of the described methods and point out unsolved problems and challenges. In addition, several case studies illustrating the application of methods and technologies used in cultural heritage are presented

Interactive volume visualization with WebGl

Web-based applications have become increasingly popular in many areas and advances in web-based 3D graphics were made accordingly. In this context, we present a web based implementation of volume rendering using the relatively new WebGL API for interactive 3D graphics. An overview of the theoretical background of volume rendering as well as of the common approaches for a GPU implementation is given, followed by detailed description of our implementation with WebGL. Afterwards the implementation of advanced features is covered, before a short introduction to X3DOM, as a possible alternative for web based volume visualization, is given. It is the aim of this work to incorporate both basic and advanced methods of volume rendering and to achieve interactive framerates with WebGL, using the power of client-side graphics hardware. With regard to that, the result of our implementation is discussed by evaluating its performance and by comparing it to an alternative solution. Finally, we draw a conclusion of our work and point out possible future work and improvements

SVG 3D Graphical Presentation for Web-based Applications

Due to the rapid developments in the field of computer graphics and computer hardware, web-based applications are becoming more and more powerful, and the performance distance between web-based applications and desktop applications is increasingly closer. The Internet and the WWW have been widely used for delivering, processing, and publishing 3D data. There is increasingly demand for more and easier access to 3D content on the web. The better the browser experience, the more potential revenue that web-based content can generate for providers and others. The main focus of this thesis is on the design, develop and implementation of a new 3D generic modelling method based on Scalable Vector Graphics (SVG) for web-based applications. While the model is initialized using classical 3D graphics, the scene model is extended using SVG. A new algorithm to present 3D graphics with SVG is proposed. This includes the definition of a 3D scene in the framework, integration of 3D objects, cameras, transformations, light models and textures in a 3D scene, and the rendering of 3D objects on the web page, allowing the end-user to interactively manipulate objects on the web page. A new 3D graphics library for 3D geometric transformation and projection in the SVG GL is design and develop. A set of primitives in the SVG GL, including triangle, sphere, cylinder, cone, etc. are designed and developed. A set of complex 3D models in the SVG GL, including extrusion, revolution, Bezier surface, and point clouds are designed and developed. The new Gouraud shading algorithm and new Phong Shading algorithm in the SVG GL are proposed, designed and developed. The algorithms can be used to generate smooth shading and create highlight for 3D models. The new texture mapping algorithms for the SVG GL oriented toward web-based 3D modelling applications are proposed, designed and developed. Texture mapping algorithms for different 3D objects such as triangle, plane, sphere, cylinder, cone, etc. will also be proposed, designed and developed. This constitutes a unique and significant contribution to the disciplines of web-based 3D modelling, as well as to the process of 3D model popularization