2,772 research outputs found

    Cosmic cookery : making a stereoscopic 3D animated movie.

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    This paper describes our experience making a short stereoscopic movie visualizing the development of structure in the universe during the 13.7 billion years from the Big Bang to the present day. Aimed at a general audience for the Royal Society's 2005 Summer Science Exhibition, the movie illustrates how the latest cosmological theories based on dark matter and dark energy are capable of producing structures as complex as spiral galaxies and allows the viewer to directly compare observations from the real universe with theoretical results. 3D is an inherent feature of the cosmology data sets and stereoscopic visualization provides a natural way to present the images to the viewer, in addition to allowing researchers to visualize these vast, complex data sets. The presentation of the movie used passive, linearly polarized projection onto a 2m wide screen but it was also required to playback on a Sharp RD3D display and in anaglyph projection at venues without dedicated stereoscopic display equipment. Additionally lenticular prints were made from key images in the movie. We discuss the following technical challenges during the stereoscopic production process; 1) Controlling the depth presentation, 2) Editing the stereoscopic sequences, 3) Generating compressed movies in display speciÂŻc formats. We conclude that the generation of high quality stereoscopic movie content using desktop tools and equipment is feasible. This does require careful quality control and manual intervention but we believe these overheads are worthwhile when presenting inherently 3D data as the result is signiÂŻcantly increased impact and better understanding of complex 3D scenes

    Stereoscopic Sketchpad: 3D Digital Ink

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    --Context-- This project looked at the development of a stereoscopic 3D environment in which a user is able to draw freely in all three dimensions. The main focus was on the storage and manipulation of the ‘digital ink’ with which the user draws. For a drawing and sketching package to be effective it must not only have an easy to use user interface, it must be able to handle all input data quickly and efficiently so that the user is able to focus fully on their drawing. --Background-- When it comes to sketching in three dimensions the majority of applications currently available rely on vector based drawing methods. This is primarily because the applications are designed to take a users two dimensional input and transform this into a three dimensional model. Having the sketch represented as vectors makes it simpler for the program to act upon its geometry and thus convert it to a model. There are a number of methods to achieve this aim including Gesture Based Modelling, Reconstruction and Blobby Inflation. Other vector based applications focus on the creation of curves allowing the user to draw within or on existing 3D models. They also allow the user to create wire frame type models. These stroke based applications bring the user closer to traditional sketching rather than the more structured modelling methods detailed. While at present the field is inundated with vector based applications mainly focused upon sketch-based modelling there are significantly less voxel based applications. The majority of these applications focus on the deformation and sculpting of voxmaps, almost the opposite of drawing and sketching, and the creation of three dimensional voxmaps from standard two dimensional pixmaps. How to actually sketch freely within a scene represented by a voxmap has rarely been explored. This comes as a surprise when so many of the standard 2D drawing programs in use today are pixel based. --Method-- As part of this project a simple three dimensional drawing program was designed and implemented using C and C++. This tool is known as Sketch3D and was created using a Model View Controller (MVC) architecture. Due to the modular nature of Sketch3Ds system architecture it is possible to plug a range of different data structures into the program to represent the ink in a variety of ways. A series of data structures have been implemented and were tested for efficiency. These structures were a simple list, a 3D array, and an octree. They have been tested for: the time it takes to insert or remove points from the structure; how easy it is to manipulate points once they are stored; and also how the number of points stored effects the draw and rendering times. One of the key issues brought up by this project was devising a means by which a user is able to draw in three dimensions while using only two dimensional input devices. The method settled upon and implemented involves using the mouse or a digital pen to sketch as one would in a standard 2D drawing package but also linking the up and down keyboard keys to the current depth. This allows the user to move in and out of the scene as they draw. A couple of user interface tools were also developed to assist the user. A 3D cursor was implemented and also a toggle, which when on, highlights all of the points intersecting the depth plane on which the cursor currently resides. These tools allow the user to see exactly where they are drawing in relation to previously drawn lines. --Results-- The tests conducted on the data structures clearly revealed that the octree was the most effective data structure. While not the most efficient in every area, it manages to avoid the major pitfalls of the other structures. The list was extremely quick to render and draw to the screen but suffered severely when it comes to finding and manipulating points already stored. In contrast the three dimensional array was able to erase or manipulate points effectively while the draw time rendered the structure effectively useless, taking huge amounts of time to draw each frame. The focus of this research was on how a 3D sketching package would go about storing and accessing the digital ink. This is just a basis for further research in this area and many issues touched upon in this paper will require a more in depth analysis. The primary area of this future research would be the creation of an effective user interface and the introduction of regular sketching package features such as the saving and loading of images

    Reflectance Transformation Imaging (RTI) System for Ancient Documentary Artefacts

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    This tutorial summarises our uses of reflectance transformation imaging in archaeological contexts. It introduces the UK AHRC funded project reflectance Transformation Imaging for Anciant Documentary Artefacts and demonstrates imaging methodologies

    Depth-Assisted Semantic Segmentation, Image Enhancement and Parametric Modeling

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    This dissertation addresses the problem of employing 3D depth information on solving a number of traditional challenging computer vision/graphics problems. Humans have the abilities of perceiving the depth information in 3D world, which enable humans to reconstruct layouts, recognize objects and understand the geometric space and semantic meanings of the visual world. Therefore it is significant to explore how the 3D depth information can be utilized by computer vision systems to mimic such abilities of humans. This dissertation aims at employing 3D depth information to solve vision/graphics problems in the following aspects: scene understanding, image enhancements and 3D reconstruction and modeling. In addressing scene understanding problem, we present a framework for semantic segmentation and object recognition on urban video sequence only using dense depth maps recovered from the video. Five view-independent 3D features that vary with object class are extracted from dense depth maps and used for segmenting and recognizing different object classes in street scene images. We demonstrate a scene parsing algorithm that uses only dense 3D depth information to outperform using sparse 3D or 2D appearance features. In addressing image enhancement problem, we present a framework to overcome the imperfections of personal photographs of tourist sites using the rich information provided by large-scale internet photo collections (IPCs). By augmenting personal 2D images with 3D information reconstructed from IPCs, we address a number of traditionally challenging image enhancement techniques and achieve high-quality results using simple and robust algorithms. In addressing 3D reconstruction and modeling problem, we focus on parametric modeling of flower petals, the most distinctive part of a plant. The complex structure, severe occlusions and wide variations make the reconstruction of their 3D models a challenging task. We overcome these challenges by combining data driven modeling techniques with domain knowledge from botany. Taking a 3D point cloud of an input flower scanned from a single view, each segmented petal is fitted with a scale-invariant morphable petal shape model, which is constructed from individually scanned 3D exemplar petals. Novel constraints based on botany studies are incorporated into the fitting process for realistically reconstructing occluded regions and maintaining correct 3D spatial relations. The main contribution of the dissertation is in the intelligent usage of 3D depth information on solving traditional challenging vision/graphics problems. By developing some advanced algorithms either automatically or with minimum user interaction, the goal of this dissertation is to demonstrate that computed 3D depth behind the multiple images contains rich information of the visual world and therefore can be intelligently utilized to recognize/ understand semantic meanings of scenes, efficiently enhance and augment single 2D images, and reconstruct high-quality 3D models

    VRChem: Virtuaalitodellisuuteen perustuva molekyylimallinnusohjelmisto

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    Understanding the often complex atomic-level three-dimensional structure of molecules and materials is crucial in chemistry,and many tools have been designed and created to help chemists visualize and examine these structures. Currently, the most popular tool is molecular modeling software designed for desktop computers. The 2D-representations of molecules these applications render, however, are not ideal for studying the three-dimensional structure, and better tools with support for true stereoscopic molecular 3D-representation are needed. For this purpose, we have created VRChem, a novel molecular modeling application for Virtual Reality featuring a modern 3D user interface. With VRChem and the necessary hardware, users can construct and modify molecules in a virtual reality environment using their bare hands. This thesis covers the development and technical details of the VRChem application and what is being planned for future versions. VRChem is built on the Unity game engine for multi-platform support and it has thus far been an adequate platform for the application. The current version was built as a prototype for user interface testing and is not suitable for professional or research use, but the planned updates, such as improved graphical user interfaces, performance optimizations and more accurate energy minimization methods could make it a functional application in the future.Molekyylien ja materiaalien usein monimutkaisen atomirakenteen ymmÀrtÀminen on ÀÀrimmÀisen tÀrkeÀÀ kemiallisessa tutkimuksessa ja reaktioiden suunnittelussa. TÀtÀ tehtÀvÀÀ varten onkin luotu useita työkaluja, joiden avulla voidaan mallintaa kemiallisia rakenteita, tutkia niiden reaktiivisuutta ja suunnitella halutun rakenteen luomista. Nykyaikana kÀytetyimmÀt mallinnustyökalut ovat tietokoneohjelmistoja, joita kÀytetÀÀn hiirellÀ ja nÀppÀimistöllÀ ja joka piirtÀÀ kuvaa rakenteesta tavalliselle tietokoneen nÀytölle. Valitettavasti nÀyttöpÀÀtteen kaksiuloitteisesta kuvasta johtuen kemiallisten yhdisteiden rakenteiden kolmiuloitteisuus, jolla on suuri merkitys reaktiivisuuteen, on tietyissÀ tilanteissa vaikea hahmottaa. TÀstÀ syystÀ alalla olisi kysyntÀÀ työkaluille, jotka kykenisivÀt tarkempaan 3D-rakenteen visualisointiin. KehittÀmÀmme VRChem-ohjelma on virtuaalitodellisuuteen perustuva stereoskooppinen molekyylimallinnusohjelma, joka kykenee erittÀin realistiseen kolmioloitteiseen molekyylien visualisointiin ja niiden muokkaamiseen kÀyttÀjÀn omin kÀsin, myös ilman kÀsissÀ pidettÀviÀ ohjaimia. TÀmÀ diplomityö kÀsittelee VRChem-ohjelman kehitystyötÀ ja teknistÀ toteutusta, ja kuinka ohjelmiston kehitystÀ voitaisiin jatkaa paremman kokemuksen tarjoamiseksi. VRChem on kehitetty Unity-pelimoottorin avulla, ja sen nykyinen prototyyppiversio on tÀysin toimiva kokonaisuus, jota on kÀytetty kÀyttÀjÀkokeissa virtuaalitodellisuuden hyödyllisyyden tutkimiseksi. Ohjelma ei ole valmis kÀytettÀvÀksi kemiallisessa tutkimuksessa tai opetuksessa, mutta suunnitellut ominaisuus- ja suorituskykyparannukset voivat tulevaisuudessa tehdÀ tÀstÀ mahdollista

    Optical techniques for 3D surface reconstruction in computer-assisted laparoscopic surgery

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    One of the main challenges for computer-assisted surgery (CAS) is to determine the intra-opera- tive morphology and motion of soft-tissues. This information is prerequisite to the registration of multi-modal patient-specific data for enhancing the surgeon’s navigation capabilites by observ- ing beyond exposed tissue surfaces and for providing intelligent control of robotic-assisted in- struments. In minimally invasive surgery (MIS), optical techniques are an increasingly attractive approach for in vivo 3D reconstruction of the soft-tissue surface geometry. This paper reviews the state-of-the-art methods for optical intra-operative 3D reconstruction in laparoscopic surgery and discusses the technical challenges and future perspectives towards clinical translation. With the recent paradigm shift of surgical practice towards MIS and new developments in 3D opti- cal imaging, this is a timely discussion about technologies that could facilitate complex CAS procedures in dynamic and deformable anatomical regions

    Innovative Approaches to 3D GIS Modeling for Volumetric and Geoprocessing Applications in Subsurface Infrastructures in a Virtual Immersive Environment

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    As subsurface features remain largely ‘out of sight, out of mind’, this has led to challenges when dealing with underground space and infrastructures and especially so for those working in GIS. Since subsurface infrastructure plays a major role in supporting the needs of modern society, groups such as city planners and utility companies and decision makers are looking for an ‘holistic’ approach where the sustainable use of underground space is as important as above ground space. For such planning and management, it is crucial to examine subsurface data in a form that is amenable to 3D mapping and that can be used for increasingly sophisticated 3D modeling. The subsurface referred to in this study focuses particularly on examples of both shallow and deep underground infrastructures. In the case of shallow underground infrastructures mostly two-dimensional maps are used in the management and planning of these features. Depth is a very critical component of underground infrastructures that is difficult to represent in a 2D map and for this reason these are best studied in three-dimensional space. In this research, the capability of 3D GIS technology and immersive geography are explored for the storage, management, analysis, and visualization of shallow and deep subsurface features
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