Interactive volume rendering using multi-dimensional transfer functions and direct manipulation widgets

Journal ArticleMost direct volume renderings produced today employ onedimensional transfer functions, which assign color and opacity to the volume based solely on the single scalar quantity which comprises the dataset. Though they have not received widespread attention, multi-dimensional transfer functions are a very effective way to extract specific material boundaries and convey subtle surface properties. However, identifying good transfer functions is difficult enough in one dimension, let alone two or three dimensions. This paper demonstrates an important class of three-dimensional transfer functions for scalar data (based on data value, gradient magnitude, and a second directional derivative), and describes a set of direct manipulation widgets which make specifying such transfer functions intuitive and convenient. We also describe how to use modern graphics hardware to interactively render with multi-dimensional transfer functions. The transfer functions, widgets, and hardware combine to form a powerful system for interactive volume exploration

Interactive volume rendering using multi-dimensional transfer functions and direct manipulation widgets

Journal ArticleMost direct volume renderings produced today employ one-dimensional transfer functions, which assign color and opacity to the volume based solely on the single scalar quantity which comprises the dataset. Though they have not received widespread attention, multi-dimensional transfer functions are a very effective way to extract specific material boundaries and convey subtle surface properties

IXI software: open controllers for open source audio software

Sound has been liberated. The 20th century freed music from various compositional constraints and ideologies, and during the last decade we have witnessed a transformation in the way sound is organized in terms of composition, production, distribution and consumption. This paper is concerned with the production part of this complex structure and will describe some of the ideas, experiments and conclusions of ixi software over the last years. ixi has been building open interfaces to be used with open source audio programming environments. We will go through which cultural and technological changes have affected our work and describe the situation of audio programming as it appears to us today, as inventors of virtual screen-based instruments

Multidimensional transfer functions for interactive volume rendering

Journal ArticleAbstract-Most direct volume renderings produced today employ one-dimensional transfer functions which assign color and opacity to the volume based solely on the single scalar quantity which comprises the data set. Though they have not received widespread attention, multidimensional transfer functions are a very effective way to extract materials and their boundaries for both scalar and multivariate data. However, identifying good transfer functions is difficult enough in one dimension, let alone two or three dimensions. This paper demonstrates an important class of three-dimensional transfer functions for scalar data, and describes the application of multidimensional transfer functions to multivariate data. We present a set of direct manipulation widgets that make specifying such transfer functions intuitive and convenient. We also describe how to use modern graphics hardware to both interactively render with multidimensional transfer functions and to provide interactive shadows for volumes. The transfer functions, widgets, and hardware combine to form a powerful system for interactive volume exploration

Using Computer Vision to Quantify Coral Reef Biodiversity

The preservation of the world’s oceans is crucial to human survival on this planet, yet we know too little to begin to understand anthropogenic impacts on marine life. This is especially true for coral reefs, which are the most diverse marine habitat per unit area (if not overall) as well as the most sensitive. To address this gap in knowledge, simple field devices called autonomous reef monitoring structures (ARMS) have been developed, which provide standardized samples of life from these complex ecosystems. ARMS have now become successful to the point that the amount of data collected through them has outstripped the capacity of research organizations to analyze through molecular methods. To facilitate these efforts, the present study explores the use of computer vision techniques to analyze the complex image data of these samples in order to extract useful information based on morphological (visual) characteristics of the collected organisms. Various techniques at varying levels of sophistry are surveyed for their suitability to the present problem. In the end, the more complex techniques are ruled out in the favor of basic image processing ones, of which three are tested: canny edge detection, color space transformations, and histogram equalization. While the first one does not directly yield useful results, the latter two turn out to be surprisingly effective, showing great promise as means to prepare data that more sophisticated techniques can be subsequently trained on. Future directions of investigation are recorded in detail, along with suggestions and relevant references, towards ultimately realizing an online analysis tool and repository for marine life that would accelerate related research and conservation efforts

\u3ci\u3eOut of the Box\u3c/i\u3e: Bridging the Long-Distance Gap Between Consumer and Product in Online Experiences by Using AR to Facilitate a Deeper Connection Through Virtual Try-Ons

As consumers are more and more preferring online experiences to brick-and-mortar shopping, there is a growing need for new and creative marketing strategies that can overcome the physical distance between consumer and product. In this paper, I demonstrate how augmented reality can bridge that gap, allowing consumers to connect with a product in a way that is not possible through traditional online media forms such as images and video. To that end, this paper includes a detailed breakdown of the conception and creation of Out of the Box, an augmented-reality application developed to enable users to virtually interact with a ring by “trying on” a ring as well as by customizing the appearance of a ring in real time

Computational medical imaging for total knee arthroplasty using visualitzation toolkit

This project is presented as a Master Thesis in the field of Civil Engineering, Biomedical specialization. As the project of an Erasmus exchange student, this thesis has been under supervision both the Universite Livre de Bruxelles and the Universitat Politecnica de Catalunya. The purpose of this thesis to put in practice all the knowledges acquired during this Master in Industrial Engineering in UPC and to be a support for medical staff in total knee arthoplasty procedures. Prof. Emmanuel Thienpont has been working for years as orthopaedic surgeon at the Hospital Sant Luc, Brussels. His years of work and research have been mainly focused on Total Knee Arthroplasty or TKA. During one of the most important steps of this procedure, the orthopaedic surgeon has to cut the head of the femur following two perpendicular cutting planes. Nevertheless, the orientation of these planes are directly dependant of the femur constitution. This Master Thesis has been conceived in order to offer the surgeon a tool to determine the proper direction planes in a previous step before the surgical procedure. This project pretends to give the surgeon an openfree computational platform to access to patient geometrical and physiological information before involving the subject in any invasive procedure

Shaderonomicon: Tool for high-level developing and exportation of shaders

Treball final de Grau en Disseny i Desenvolupament de Videojocs. Codi: VJ1241. Curs acadèmic: 2017/2018Computer graphics is a branch of computer science that involves the treatment of everything that could appear on a screen. In the past years, this field has become one of the most important for video game developers, as it provides a tool for easy but powerful optimization solutions, and a huge improvement in visual quality. As interesting as it may sound, the greatest barrier to learn about it is the difficulty of its intern calculations and structure. As it requires not only to learn/adapt oneself to a programming language (in this case, nvidia CG is a C-based language), it also requires more advanced mathematical knowledge, regarding matrix operations. Fortunately, in the recent years, this barrier was tightened by tools that use an object-based programming, the node-based shader edition. This type of edition allows the user to create shaders in a more visual way, using objects with linkable properties, and let us see the result in real-time. This type of tool has overcomed the hurdle of using a programming language, but it still requires specific mathematical knowledge to dig out its full potential. An example of this type of tool is the Shader Graph​[1]​, the node-based shader editor included inside Unity3D​[2]​. Shaderonomicon is a tool which aims to surpass the previously mentioned limitations, and give access to any developer to basic shader edition, in an intuitive and easy way. By using this application, one can understand which basic properties have a texture​[3]​, normal map​[4]​, or how lighting models affect the overall quality of the shader’s output, and how all of these features interact with each other. The target audience of Shaderonomicon involves anyone without prior shader knowledge, who wants to learn in a direct way how does a shader works, and experiment with basic features without writing a line of code. Because of its easy-to-export and multi-platform operability, Unity3D is the best platform, not only to implement the application’s systems, but also the most efficient one for the shader to be exported to

View-dependent Exploration of Massive Volumetric Models on Large Scale Light Field Displays

We report on a light-field display based virtual environment enabling multiple naked-eye users to perceive detailed multi-gigavoxel volumetric models as floating in space, responsive to their actions, and delivering different information in different areas of the workspace. Our contributions include a set of specialized interactive illustrative techniques able to provide different contextual information in different areas of the display, as well as an out-of-core CUDA based raycasting engine with a number of improvements over current GPU volume raycasters. The possibilities of the system are demonstrated by the multi-user interactive exploration of 64GVoxels datasets on a 35MPixel light field display driven by a cluster of PCs.1037-1047Pubblicat