PrePrint: XML3D and Xflow: Combining Declarative 3D for the Web with Generic Dataflows
Xflow is a system for declarative, high-performance data processing. In combination with XML3D, it allows Web developers to combine a 3D scene graph with dataflows for dynamic meshes, animations, image processing, post processing, and Augmented Reality.
PrePrint: Fast and Progressive Loading of Binary Encoded Declarative 3D Web Content
Until recently, the encoding of scene-graph related structured data along with a text-based description of unstructured vertex data has been a major drawback of declarative 3D approaches for the Web. In addition to long loading times, 3D Web content was not available at all until the full page had been completely loaded. To overcome this limitation, external mesh data containers, which are referenced in the scene description, have to be used. We discuss the use of Sequential Image Geometry (SIG) containers and explicit binary containers, which are well-aligned to buffer structures on the GPU and therefore enable fast decoding and GPU upload. We furthermore investigate the potential of progressive binary formats within the Web environment by introducing a new method called Progressive Binary Geometry (PBG), which enables a simple yet highly progressive transmission of arbitrary mesh data on the Web.
PrePrint: The LiverAnatomyExplorer: A WebGL-based Surgical Teaching Tool
The purpose of this article is the presentation of a real-time Web3D surgical teaching tool: the LiverAnatomyExplorer. We propose an overall architecture for web-based medical learning systems and utilize this architecture for the development of our learning module. The online tool is based on state-of-the-art web technologies such as SVG, X3D and WebGL. In contrast to existing medical e-learning systems, we provide interactive web-based 3D models of patient anatomy derived from patient-specific image data, and combine them with traditional clinical 2D imagery. The LiverAnatomy-Explorer is enhanced by surgical movies, a self-assessment tool and an online authoring framework that can be deployed by tutors to manage patient cases and multiple choice quizzes. The presented Web3D e-learning tool shall support traditional educational methods such as lectures and textbooks. The promising evaluation results confirm this assumption.
PrePrint: A Video-based Interface for Hand-Driven Stop Motion Animation Production
Stop motion is a well-established animation technique, but its production is often laborious and requires craft skills. We present a new video-based interface which is capable of animating the vast majority of everyday objects in stop motion style in a more flexible and intuitive way. It allows animators to perform and capture motions continuously instead of breaking them into small increments and shooting one still picture per increment. More importantly, it permits direct hand manipulation without resorting to rigs, achieving more natural object control for beginners. The key component of our system is a two-phase keyframe-based capturing and processing workflow, assisted by computer vision techniques. We demonstrate that our system is efficient even for amateur animators to generate high quality stop motion animations of a wide variety of objects.
PrePrint: GPU-Accelerated Interactive Visualization and Planning of Neurosurgical Interventions
Advances in computational methods and hardware platforms provide efficient processing of medical imaging data sets for surgical planning. In the case of neurosurgical interventions that are performed via a straight access path, planning entails selecting a pathway, from the scalp surface to the targeted area, that is of minimal risk to the patient. We propose a GPU-accelerated approach to enable quantitative estimation of the risk associated with a particular access path at interactive rates. It heavily exploits spatially accelerated data structures and efficient implementation of algorithms on GPUs. We evaluate the computational efficiency and scalability of the proposed approach through extensive performance comparisons, and show that interactive rates can be achieved even for high-resolution meshes. Through a user study, and feedback obtained from domain experts, we identify some of the potential benefits that our high-speed approach offers for pre-operative planning and intra-operative replanning of straight access neurosurgical interventions.