@article{Schernthaner-2017-MCP, title = "Multipath Curved Planar Reformations of Peripheral CT Angiography: Diagnostic Accuracy and Time Efficiency", author = "Markus Schreiner and Hannes Platzgummer and Sylvia Unterhumer and Michael Weber and Gabriel Mistelbauer and Eduard Gr\"{o}ller and Christian Loewe and R\"{u}diger Schernthaner", year = "2018", abstract = "Objectives To compare diagnostic performance and time efficiency between 3D multipath curved planar reformations (mpCPRs) and axial images of CT angiography for the pre-interventional assessment of peripheral arterial disease (PAD), with digital subtraction angiography as the standard of reference. Methods Forty patients (10 females, mean age 72 years), referred to CTA prior to endovascular treatment of PAD, were prospectively included and underwent peripheral CT angiography. A semiautomated toolbox was used to render mpCPRs. Twenty-one arterial segments were defined in each leg; for each segment, the presence of stenosis[70% was assessed on mpCPRs and axial images by two readers, independently, with digital subtraction angiography as gold standard. Results Both readers reached lower sensitivity (Reader 1: 91 vs. 94%, p = 0.08; Reader 2: 89 vs. 93%, p = 0.03) but significantly higher specificity (Reader 1: 94 vs. 89%, p\0.01; Reader 2: 96 vs. 95%, p = 0.01) with mpCPRs than with axial images. Reader 1 achieved significantly higher accuracy with mpCPRs (93 vs. 91%, p = 0.02), and Reader 2 had similar overall accuracy in both evaluations (94 vs. 94%, p = 0.96). Both readers read mpCPRs significantly faster than axial images (Reader 1: 504500 based on mpCPRs vs. 704000 based on axial images; Reader 2: 404100 based on mpCPRs vs. 605700 based on axial images; p\0.01). Conclusions mpCPRs are a promising 3D reformation technique that facilitates a fast assessment of PAD with high diagnostic accuracy.", month = may, doi = "10.1007/s00270-017-1846-3", issn = "0174-1551", journal = "CardioVascular and Interventional Radiology", number = "5", volume = "41", pages = "718--725", keywords = "PAD, CTA, 3D reformation, mpCPRs", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/Schernthaner-2017-MCP/", } @talk{sbert-2017-sa_course_0023, title = "Information Theory In Visualization", author = "Mateu Sbert and Han-Wei Shen and Ivan Viola and Min Chen and Anton Bardera and Miquel Feixas", year = "2017", month = nov, event = "SIGGRAPH Asia 2017 Course 0023", location = "Bangkok, Thailand", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/sbert-2017-sa_course_0023/", } @bachelorsthesis{unger_2017, title = "Evaluation of Machine Learning Frameworks on Tuberculosis Classification of Chest Radiographs", author = "Katharina Unger", year = "2017", abstract = "In this thesis different state-of-the-art machine learning frameworks were implemented and evaluated on chest radiographs to classify them into tuberculotic or healthy radiographs. Traditional explicit feature engineering was performed, as well as different deep learning approaches were applied. For the deep learning experiments different publicly available architectures were compared in two different tasks. The first task with deep learning was to use a Convolutional Neural Network, already trained on a different task, to extract features of the chest radiographs. These features were then classified separately. The second experiment was to use a Convolutional Neural Network, again pretrained on a different task, and train this network carefully again on the chest radiographs. The results of the different frameworks were summarized, evaluated and presented in tables.", month = nov, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/unger_2017/", } @phdthesis{waldin-2017-thesis, title = "Using and Adapting to Limits of Human Perception in Visualization", author = "Nicholas Waldin", year = "2017", month = nov, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/waldin-2017-thesis/", } @talk{Groeller-2017-ARTORW, title = "A Random Talk on Random Walks", author = "Eduard Gr\"{o}ller", year = "2017", month = oct, event = "10 Years Bergen VisGroup Celebration", location = "University of Bergen, Norway", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Groeller-2017-ARTORW/", } @article{santos-2017-dacge, title = "Distinctive Approaches to Computer Graphics Education", author = "Beatriz Sousa Santos and Jean-Michel Dischler and Valery Adzhiev and Eike Falk Anderson and Andrej Ferko and Oleg Fryazinov and Martin Il\v{c}\'{i}k and Ivana Il\v{c}\'{i}kov\'{a} and P. Slavik and Veronica Sundstedt and Lucie Svobodova and Michael Wimmer and Jiri Zara", year = "2018", abstract = "This paper presents the latest advances and research in Computer Graphics education in a nutshell. It is concerned with topics that were presented at the Education Track of the Eurographics Conference held in Lisbon in 2016. We describe works corresponding to approaches to Computer Graphics education that are unconventional in some way and attempt to tackle unsolved problems and challenges regarding the role of arts in computer graphics education, the role of research-oriented activities in undergraduate education and the interaction among different areas of Computer Graphics, as well as their application to courses or extra-curricular activities. We present related works addressing these topics and report experiences, successes and issues in implementing the approaches.", month = feb, doi = "10.1111/cgf.13305", issn = "1467-8659", journal = "Computer Graphics Forum", number = "1", volume = "37", pages = "403--412", keywords = "Computer Graphics Education", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/santos-2017-dacge/", } @studentproject{OPPITZ-2017-3DM, title = "3D Mass Customization: Real-Time High-Quality Lighting Effects for WebGL", author = "Michael Oppitz", year = "2017", abstract = "During the internship at ShapeDiver GmbH the visual quality of an existing WebGL platform had to be improved. This platform is used as an online 3D configurator, in which customers can modify the properties of parametric models. This includes the modification of properties like shape, size and materials. The difficulty for this project was to contemplate the fact that the product can be customized by the user in real-time.", month = oct, URL = "https://www.cg.tuwien.ac.at/research/publications/2017/OPPITZ-2017-3DM/", } @article{HU-2017-ETM, title = "Efficient Tree Modeling from Airborne LiDAR Point Clouds", author = "Shaojun Hu and Zhengrong Li and Zhiyi Zhang and Dongijan He and Michael Wimmer", year = "2017", abstract = "Modeling real-world trees is important in many application areas, including computer graphics, botany and forestry. An example of a modeling method is reconstruction from light detection and ranging (LiDAR) scans. In contrast to terrestrial LiDAR systems, airborne LiDAR systems – even current high-resolution systems – capture only very few samples on tree branches, which makes the reconstruction of trees from airborne LiDAR a challenging task. In this paper, we present a new method to model plausible trees with fine details from airborne LiDAR point clouds. To reconstruct tree models, first, we use a normalized cut method to segment an individual tree point cloud. Then, trunk points are added to supplement the incomplete point cloud, and a connected graph is constructed by searching sufficient nearest neighbors for each point. Based on the observation of real-world trees, a direction field is created to restrict branch directions. Then, branch skeletons are constructed using a bottom-up greedy algorithm with a priority queue, and leaves are arranged according to phyllotaxis. We demonstrate our method on a variety of examples and show that it can generate a plausible tree model in less than one second, in addition to preserving features of the original point cloud.", month = oct, issn = "0097-8493", journal = "Computers & Graphics", volume = "67", pages = "1--13", keywords = "tree modeling, LIDAR, point clouds", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/HU-2017-ETM/", } @article{mindek-2017-dsn, title = "Data-Sensitive Visual Navigation", author = "Peter Mindek and Gabriel Mistelbauer and Eduard Gr\"{o}ller and Stefan Bruckner", year = "2017", abstract = "In visualization systems it is often the case that the changes of the input parameters are not proportional to the visual change of the generated output. In this paper, we propose a model for enabling data-sensitive navigation for user-interface elements. This model is applied to normalize the user input according to the visual change, and also to visually communicate this normalization. In this way, the exploration of heterogeneous data using common interaction elements can be performed in an efficient way. We apply our model to the field of medical visualization and present guided navigation tools for traversing vascular structures and for camera rotation around 3D volumes. The presented examples demonstrate that the model scales to user-interface elements where multiple parameters are set simultaneously.", month = oct, journal = "Computers & Graphics", volume = "67", number = "C", pages = "77--85", keywords = "navigation, exploration, medical visualization", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/mindek-2017-dsn/", } @phdthesis{preiner_2017_phd, title = "Dynamic and Probabilistic Point-Cloud Processing", author = "Reinhold Preiner", year = "2017", month = oct, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/preiner_2017_phd/", } @article{Diehl-2017-Albero, title = "Albero: A Visual Analytics Approach for Probabilistic Weather Forecasting", author = "Alexandra Diehl and Leandro Pelorosso and Claudio Delrieux and Kresimir Matkovic and Eduard Gr\"{o}ller and Stefan Bruckner", year = "2017", abstract = "Probabilistic weather forecasts are amongst the most popular ways to quantify numerical forecast uncertainties. The analog regression method can quantify uncertainties and express them as probabilities. The method comprises the analysis of errors from a large database of past forecasts generated with a specific numerical model and observational data. Current visualization tools based on this method are essentially automated and provide limited analysis capabilities. In this paper, we propose a novel approach that breaks down the automatic process using the experience and knowledge of the users and creates a new interactive visual workflow. Our approach allows forecasters to study probabilistic forecasts, their inner analogs and observations, their associated spatial errors, and additional statistical information by means of coordinated and linked views. We designed the presented solution following a participatory methodology together with domain experts. Several meteorologists with different backgrounds validated the approach. Two case studies illustrate the capabilities of our solution. It successfully facilitates the analysis of uncertainty and systematic model biases for improved decision-making and process-quality measurements.", month = oct, journal = "Computer Graphics Forum 36(7) 135-144 (2017)", doi = "10.1111/cgf.13279", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Diehl-2017-Albero/", } @article{leimer_2017_rbpesc, title = "Relation-Based Parametrization and Exploration of Shape Collections", author = "Kurt Leimer and Lukas Gersthofer and Michael Wimmer and Przemyslaw Musialski", year = "2017", abstract = "With online repositories for 3D models like 3D Warehouse becoming more prevalent and growing ever larger, new possibilities have emerged for both experienced and inexperienced users. These large collections of shapes can provide inspiration for designers or make it possible to synthesize new shapes by combining different parts from already existing shapes, which can be both easy to learn and a fast way of creating new shapes. But exploring large shape collections or searching for particular kinds of shapes can be difficult and time-consuming tasks as well, especially considering that online repositories are often disorganized. In our work, we propose a relation-based way to parametrize shape collections, allowing the user to explore the entire set of shapes based on the variability of spatial arrangements between pairs of parts. The way in which shapes differ from each other is captured automatically, resulting in a small number of exploration parameters. Furthermore, a copy-and-paste system for parts allows the user to change the structure of a shape, making it possible to explore the entire collection from any initial shape.", month = oct, issn = "0097-8493", journal = "Computers & Graphics", volume = "67", pages = "127--137", keywords = "3d database exploration, Model variability, Shape analysis, Shape collections", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/leimer_2017_rbpesc/", } @talk{Purgathofer-2017-China2, title = "From Visualization to Decision Support", author = "Werner Purgathofer", year = "2017", month = sep, event = "2nd International Forum on VR Visual Computing Technologies", location = "Hangzhou, China", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Purgathofer-2017-China2/", } @WorkshopTalk{Groeller-2017-AMOS, title = "A Matter of Scale", author = "Eduard Gr\"{o}ller", year = "2017", abstract = "Scale and scalability have been recurring topics in our field. Recent developments like smart data, machine learning, and advances in domains like biology, cartography, smart communities, and communication pose novel challenges to scalability and use of scale. Examples include scale-transparent visual computing, cross-scale visualization and interaction, massive multi-scale techniques, scale integration, cross-scale labeling and annotation, cross scales on structure and dynamics, and continuous scales", month = sep, event = "Molecular Animation Summit", location = "University of Utah, SCI", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Groeller-2017-AMOS/", } @talk{Purgathofer-2017-China1, title = "From Visualization to Decision Support", author = "Werner Purgathofer", year = "2017", month = sep, event = "Virtual Reality and Visual Computing International Forum", location = "Nanjing, China", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Purgathofer-2017-China1/", } @phdthesis{sorger-2017-thesis, title = "Integration Strategies in the Visualization of Multifaceted Spatial Data", author = "Johannes Sorger", year = "2017", abstract = "Visualization designers have several visual channels at their disposal for encoding data into visual representations, e.g., position, size, shape, orientation, color, texture, brightness, as well as motion. The mapping of attributes to visual channels can be chosen by the designer. In theory, any data attribute can be represented by any of these visual channels or by a combination of multiple of these channels. In practice, the optimal mapping and the most suitable type of visualization strongly depend on the data as well as on the user's task. In the visualization of spatial data, the mapping of spatial attributes to visual channels is inherently given by the data. Multifaceted spatial data possesses a wide range of additional (non-spatial) attributes without a given mapping. The data's given spatial context is often important for successfully fulfilling a task. The design space in spatial data visualization can therefore be heavily constrained when trying to choose an optimal mapping for other attributes within the spatial context. To solve an exploration or presentation task in the domain of multifaceted spatial data, special strategies have to be employed in order to integrate the essential information from the various data facets in an appropriate representation form with the spatial context. This thesis explores visualization integration strategies for multifaceted spatial data. The first part of this thesis describes the design space of integration in terms of two aspects: visual and functional integration. Visual integration describes how representations of the different data facets can be visually composed within a spatial context. Functional integration, describes how events that have been triggered, for instance, through user interaction, can be coordinated across the various visually integrated representations. The second part of this thesis describes contributions to the field of visualization in the context of concrete integration applications for exploration and presentation scenarios. The first scenario addresses a set of challenges in the exploratory analysis of multifaceted spatial data in the scope of a decision making scenario in lighting design. The user's task is to find an optimal lighting solution among dozens or even hundreds of potential candidates. In the scope of a design study, the challenges in lighting design are addressed with LiteVis, a system that integrates representations of the simulation parameter space with representations of all relevant aspects of the simulation output. The integration of these heterogeneous aspects together with a novel ranking visualization are thereby the key to enabling an efficient exploration and comparison of lighting parametrizations. In presentation scenarios, the generation of insights often cannot rely on user interaction and therefore needs a different approach. The challenge is to generate visually appealing, yet information-rich representations for mainly passive observation. In this context, this thesis addresses two different challenges in the domain of molecular visualization. The first challenge concerns the conveying of relations between two different representations of a molecular data set, such as a virus. The relation is established via animated transitions - a temporal form of integration between two representations. The proposed solution features a novel technique for creating such transitions that are re-usable for different data sets, and can be combined in a modular fashion. Another challenge in presentation scenarios of multifaceted spatial data concerns the presentation of the transition between development states of molecular models, where the actual biochemical process of the transition is not exactly known or it is too complex to represent. A novel technique applies a continuous abstraction of both model representations to a level of detail at which the relationship between them can be accurately conveyed, in order to overcome a potential indication of false relationship information. Integration thereby brings the different abstraction levels and the different model states into relation with each other. The results of this thesis clearly demonstrate that integration is a versatile tool in overcoming key challenges in the visualization of multifaceted spatial data. ", month = sep, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/sorger-2017-thesis/", } @bachelorsthesis{dodik-2017-pcbpt, title = "Implementing Probabilistic Connections for Bidirectional Path Tracing in the Mitsuba Renderer", author = "Nikola Dodik", year = "2017", abstract = "Light transport simulation algorithms are remarkably adept at recreating a large variety of light phenomena which occur in nature. As such they have seen widespread adoption across the industry, which made it paramount to create efficient and robust algorithms. One recent algorithm which tries to deal with this problem is known as Probabilistic Connections for Bidirectional Path Tracing (PCBPT). It builds upon the classical Bidirectional Path Tracing (BDPT) algorithm. In Bidirectional Path Tracing, a ray is traced from the sensor as well as from the emitter. The two rays are then connected to calculate the light contribution to image pixels. PCBPT extends this idea to support connecting multiple emitter paths to one sensor subpath, and introduces importance sampling as a way of choosing the most suitable emitter paths. Unfortunately, there was no implementation of PCBPT publically available, which is why we implemented it into the open-source Mitsuba renderer. We evaluate the algorithm against standard BDPT on a variety of different scenes. Our comparisons provide insight into what type of scenes PCBPT can help improve and where the additional computational cost presents too much of an overhead.", month = sep, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "physically based rendering, Monte Carlo rendering, bidirectional path tracing, probabilistic connections for bidirectional path tracing, Mitsuba, importance sampling", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/dodik-2017-pcbpt/", } @article{ZOTTI-2017-BM, title = "Beyond 3D Models: Simulation of Temporally Evolving Models in Stellarium", author = "Georg Zotti and Florian Schaukowitsch and Michael Wimmer", year = "2017", abstract = "In recent years, the interactive visual exploration and demonstration of three-dimensional virtual models of buildings or natural structures of archaeoastronomical interest under a simulated sky has become available for users of the open-source desktop planetarium program Stellarium [Zotti, 2015, 2016]. Users can load an architectural model in the well-known OBJ format and walk around to explore sight lines or light-and-shadow interaction in present and past times [Frischer et al., 2016]. However, until now, the model itself did not change in time, and loading models for various building phases (e.g., the assumed order of building the various standing stones, timber circles and stone circles of Stonehenge) always required a break in simulation and user interaction to load a model for the next phase. On the other hand, displaying a model under the sky of the wrong time may lead to inappropriate conclusions. Large-area models required considerable time to load, and loading caused a reset of location, so the user interested in changes in a certain viewing axis had to recreate that view again. Given that Stellarium is an “astronomical time machine”, nowadays capable of replaying sky vistas thousands of years ago with increasing accuracy [Zotti et al., submitted] and also for models with several million triangular faces, it seemed worth to explore possibilities to also show changes over time in the simulated buildings. The Scenery3D plugin of Stellarium is, however, not a complete game engine, and replicating the infrastructure found in such game engines like Unity3D – for example to interactively move game objects, or load small sub-components like standing stones and place them at arbitrary coordinates – seemed overkill. The solution introduced here is remarkably simple and should be easily adoptable for the casual model-making researcher: the MTL material description for the model, a simple plain-text file that describes colour, reflection behaviour, photo-texture or transparency of the various parts of the object, can be extended for our rendering system. Newly introduced values describe dates where parts of the model can appear and disappear (with transitional transparency to allow for archaeological dating uncertainties). The model parts with these enhanced, time-aware materials appear to fade in during the indicated time, will be fully visible in their “active” time, and will fade out again when Stellarium is set to simulate the sky when the real-world structures most likely have vanished. The only requirement for the model creator is now to separate objects so that they receive unique materials that can then be identified and augmented with these entries in the MTL text file. The advantages of this new feature should be clear: an observer can remain in a certain location in the virtual model and let the land- and skyscape change over decades or centuries, without the need to load new models. This allows the simulation of construction and reconstruction phases while still always keeping particularly interesting viewpoints unchanged, and will always show the matching sky for the most appropriate reconstruction phase of the model. ", month = sep, journal = "Mediterranean Archaeology and Archaeometry", volume = "18", number = "4", issn = "1108-9628", doi = "10.5281/zenodo.1477972", booktitle = "25th SEAC Conference", pages = "501--506", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/ZOTTI-2017-BM/", } @bachelorsthesis{Knapp_2017_CVR, title = "Explorable Semiconductors: Interacting with Crystal Structures in Virtual Reality", author = "Jakob Knapp", year = "2017", abstract = "Due to Virtual Reality’s recent rise in popularity, other application areas apart from the entertainment sector have shown interest to use VR applications for their purposes. In this thesis, a VR simulation, which enables the user to maneuver an electron through a virtual semiconductor’s crystalline atomic structure, is devised on behalf of the Institute of Microelectronics at the TU Wien. The application is based upon the cellVIEW framework, which was developed using the Unity game engine to visualize large sets of biomolecular data in real time. At first, background regarding the topic at hand is provided by defining what VR is, how it is achieved and how it has evolved from Charles Wheatstone’s stereoscope to the HTC Vive VR system. Building upon that knowledge, the reader is introduced to the main problems that research in the field of Virtual Reality is currently facing, especially considering the avoidance of VR sickness. For the development of the simulation devised in the course of this thesis, two main obstacles had to be overcome: moving the user through the virtual world without causing discomfort and handling collisions between the electron and the thousands of atoms in the crystal structure without losing performance. To address the first issue, related work is reviewed and drawn inspiration from. To avoid “vection”, movement in our simulation is limited to the forward direction and external forces are applied to a sphere representing the electron instead of influencing the user himself. To keep the frame-rate high despite the potentially large number of atoms in the virtual scene, a space-partitioning octree data-structure has been implemented. ", month = sep, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Knapp_2017_CVR/", } @bachelorsthesis{Michl_2017_CSV, title = "Generation and Visualisation of Crystal Structures", author = "Gerald Michl", year = "2017", abstract = "The semiconductor industry has been experiencing an inexorable upward trend since its emergence almost 60 years ago, with ever since advancing technology. The development of continually smaller chips makes it possible to integrate small everyday objects such as keys or watches into the digital world. An important component of these chips are transistors, which are built up internally of at least one semiconductor. This thesis deals with these semiconductors and presents a 3D game developed with Unity3D, which makes it possible to take look inside a transistor and explore it interactively. The player therefore has control of an electron flying through the crystal. However, this flight through the crystal is not free from obstacles. In the middle of the structure there are consistently occurring oxide layers which, if the electrons speed is too low, prevent the passage and repel the electron. Only at a correspondingly high speed is it possible to tunnel trough them. However, the focus is on the fact that the user can adjust the scene, partly interactively, by means of various parameters and thus can generate all possible semiconductor structures. This is not only suitable for viewing and learning different structural shapes and their symmetries, but also changes the playing experience and the degree of difficulty. The implementation is based on cellVIEW, a tool for the visualization of extensive molecular structures, which allows us to perform high-performance rendering of semiconductor structures of often far more than 15 million atoms, which implies, as the results at the end of the work show, really impressively large crystals.", month = sep, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Michl_2017_CSV/", } @bachelorsthesis{FRAISS-2017-PCU, title = "Rendering Large Point Clouds in Unity", author = "Simon Maximilian Fraiss", year = "2017", abstract = "In this thesis, a point-cloud renderer was developed in the game engine Unity. The focus lies especially on very big point clouds with several millions or billions of points, which cannot be loaded completely into memory. Special data structures and algorithms are needed to load and render continuously only the parts of the point-cloud that are relevant for the current camera position. The result is an efficient rendering system with variable settings and various rendering methods. The project is available on GitHub. ", month = sep, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "point clouds, unity", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/FRAISS-2017-PCU/", } @inproceedings{kroesl-2017-LiteMaker, title = "LiteMaker: Interactive Luminaire Development using Progressive Photon Tracing and Multi-Resolution Upsampling", author = "Katharina Kr\"{o}sl and Christian Luksch and Michael Schw\"{a}rzler and Michael Wimmer", year = "2017", abstract = "Industrial applications like luminaire development (the creation of a luminaire in terms of geometry and material) or lighting design (the efficient and aesthetic placement of luminaires in a virtual scene) rely heavily on high realism and physically correct simulations. Using typical approaches like CAD modeling and offline rendering, this requirement induces long processing times and therefore inflexible workflows. In this paper, we combine a GPU-based progressive photon-tracing algorithm to accurately simulate the light distribution of a luminaire with a novel multi-resolution image-filtering approach that produces visually meaningful intermediate results of the simulation process. By using this method in a 3D modeling environment, luminaire development is turned into an interactive process, allowing for real-time modifications and immediate feedback on the light distribution. Since the simulation results converge to a physically plausible solution that can be imported as a representation of a luminaire into a light-planning software, our work contributes to combining the two former decoupled workflows of luminaire development and lighting design, reducing the overall production time and cost for luminaire manufacturers. ", month = sep, isbn = "978-3-03868-049-9", publisher = "The Eurographics Association", location = "Bonn, Germany", event = "VMV 2017", editor = "Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao", doi = "10.2312/vmv.20171253", booktitle = "Vision, Modeling & Visualization", pages = "1--8", keywords = "Computing methodologies, Ray tracing, Image processing, Mesh geometry models", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/kroesl-2017-LiteMaker/", } @talk{Groeller-2017-AVC, title = "Adaptive Visual Computing", author = "Eduard Gr\"{o}ller", year = "2017", abstract = "Visual computing uses computer-supported, interactive, visual representations of (abstract) data to amplify cognition. In recent years data complexity concerning volume, veracity, velocity, and variety has increased considerably. Several adaptive visual computing approaches are discussed in detail. Data-sensitive navigation for user-interface elements is presented. The approach normalizes user input according to visual change, and also visually communicates this normalization. In this way, output-sensitive interactions can be realized. Quantitative and reproducible linking & brushing as integral part of visual analytics is approached through structured brushing, percentile brushes, linked statistics, and change visualization. Multiscale models, e.g., from structural biology, require multiscale dynamic color mapping with sometimes overlapping or contradicting colors. We present a technique, which adaptively, based on the current scale level, nonlinearly and seamlessly adjusts the color scheme to depict or distinguish the currently best visible structural information. Adaptive visual computing is addressing the amplified data complexity through increased scalability. Research challenges and directions are sketched at the end of the talk. ", month = aug, event = "Visit of University of Konstanz", location = "University of Konstanz", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Groeller-2017-AVC/", } @bachelorsthesis{LEOPOLD-2017-ALG, title = "Algorithmic Botany via Lindenmayer Systems in Blender", author = "Nikole Leopold", year = "2017", abstract = "Lindenmayer systems, or L-systems, are a well-established and thoroughly studied concept in the field of computer graphics. Originally introduced by theoretical botanist Aristid Lindenmayer to model the development of simple multicellular organisms, they are now commonly associated with the modeling of whole plants and complex branching structures. Various extensions such as stochastic, parametric and context-sensitive L-systems have been introduced to the formalism, allowing the modeling of stochastic, continuous growth and complex interactions of plant organisms with each other and with the external environment. More specialized interactive techniques are arguably better suited to more intuitively and predictably produce plant structures where artistic control is essential. Nonetheless, L-systems remain a fascinating and powerful methodology as they allow for the description of patterns of astonishing diversity via simple formal rules of production and graphical interpretation of the results. Small changes to these rules often yield unexpected but aesthetically fascinating results and the plethora of forms and patterns thus produced constitute a subject of study that is highly worthwhile in itself. The focus of this work is not to present novel techniques for the aesthetic or biological modeling of plants. This work aims at integrating the existing formalism of parametric, context-sensitive L-systems in a widely used open-source computer graphics software like Blender in the form of an add-on, as well as to discuss the potential advantages of such an integration. In this regard, special consideration is given to allow the modeling of environmental interaction of a growing structure with a Blender scene.", month = aug, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "l-systems, algorithmic botany", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/LEOPOLD-2017-ALG/", } @bachelorsthesis{koeppel-2016-baa, title = "Extracting Noise Models – considering X / Y and Z Noise", author = "Thomas K\"{o}ppel", year = "2017", abstract = "We have developed two different test setups allowing the characterization of noise in X, Y and Z direction for the KinectV2 and the Phab2Pro depth sensors. We have combined these two methods, generating a single noise model allowing a prediction of the amount of noise in specific areas of an image in the three respective directions at a certain distance and rotation. We have conducted two test setups and measured the noise from 900 mm to 3.100 mm for the generation of the noise models. The test setup of this thesis focused on determining the noise in X, Y and Z direction, covering the whole frustum of the respective depth sensor. In this thesis, Z noise was measured against a wall and X and Y noises were measured using a 3D chequerboard that was shifted through the room, allowing the above mentioned coverage of the whole frustum. Along the edges of the cells of the chequerboard, the X and Y noise was measured. The combined model was evaluated by using a solid cube to classify the quality of our noise model.", month = aug, note = "1", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "noise model, surface reconstruction, sensor noise", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/koeppel-2016-baa/", } @bachelorsthesis{grossmann-2016-baa, title = "Extracting Sensor Specific Noise Models", author = "Nicolas Grossmann", year = "2017", abstract = "With the growing number of consumer-oriented depth sensors like the Kinect or the newly released Phab2Pro, the question of how precise these sensors are arises. In this thesis we want to evaluate the average noise in the generated depth measurements in both the axial direction and the lateral directions. As part of a two-part project this thesis will view the noise’s development with varying distance and angle. Finally, we will present and evaluate two models describing the noise behavior, with the first being derived from solely this thesis’ measurements and the second one being a combination of the previous model and a model of a colleague. This derived models can be used in a post-processing step to filter the generated depth images.", month = aug, note = "1", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "noise model, surface reconstruction, sensor noise", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/grossmann-2016-baa/", } @bachelorsthesis{brandstaetter_01, title = "Implementation and Evaluation of a Fish-Eye Lens for Interactive Visualization of Features in Volumetric Datasets", author = "Klara Brandst\"{a}tter", year = "2017", abstract = "The exploration of data visualisations has become an important task and already reaches beyond scientific purposes. Especially, in material sciences and related industries, data analysis is crucial for the detection of possible error sources or weak spots, that occurred during fabrication, to meet the required quality criteria. open_iA is an open source software that offers such data analysis of computed tomography material data. This thesis addresses the topic of data exploration by implementing and integrating a 2D fish-eye lens into open_iA. The fish-eye lens has been chosen due to its magnification characteristics, that provide focus and context at the same time. The distinct distortion of the fish-eye lens was achieved by applying a thin-plate spline (TPS2) transformation to the dataset. Beside the fish-eye lens, there exist many more magic lenses for different kinds of datasets and purposes, which will be introduced in a few words. Furthermore, the hard- and software requirements for the fish-eye lens as well as general design concepts are defined. Then, a detailed explanation of the thin-plate spline transformation and its algorithm is given and illustrated with example datasets and step-by-step calculations. Finally, the fish-eye lens is tested for its functionality and usability with material datasets. ", month = aug, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/brandstaetter_01/", } @bachelorsthesis{ESBERGER-2016-AHO, title = "A History of Austrian Computer Games", author = "Sebastian Esberger", year = "2017", abstract = "Videospiele sind nicht nur eine der modernsten Unterhaltungs- und Kunstmedien, sondern auch eine der am schnelllebigsten. Trotz der Tatsache, dass erst seit 45 Jahren Videospiele existieren, sind bereits viele Informationen dar\"{u}ber verloren gegangen. In \"{O}sterreich begann der Videospiele-Boom erst um 1990 herum, trotzdem sind auch hier schon viele Informationen verloren gegangen. Diese Arbeit soll auf den folgenden Seiten zeigen, wie das Projekt ”A History of Austrian Computer Games” durchgef\"{u}hrt wurde, um Informationen \"{u}ber die \"{o}sterreichische Spiellandschaft zu erhalten. Unter anderem wurde dazu ein Webauftritt erstellt, welcher die Spielegeschichte in einer Datenbank festh\"{a}lt und \"{o}ffentlich verf\"{u}gbar macht. Interviews von Gr\"{u}nder und Entwickler der damaligen Szene zeigen aber auch die pers\"{o}nliche Sicht auf die Ereignisse der Vergangenheit.", month = aug, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/ESBERGER-2016-AHO/", } @bachelorsthesis{Zusag-2017-Bach, title = "Deep Learning Architectures for vessel Segmentation in 2D and 3D Biomedical Images", author = "Mario Zusag", year = "2017", abstract = "The aim of this thesis is to describe deep learning approaches for vessel segmentation in 2 and 3-dimensional biomedical images and the results achieved from these approaches on specific sets of data. The first chapter introduces the objective of this thesis, describes the data, which was used for the training, gives a short overview of machine learning and covers some theoretical aspects of artificial neural networks and especially of convolutional neural networks. The second chapter describes methods that were used for achieving the segmentation in 2 and 3 dimensions, like preprocessing of the images, algorithmic approaches, and general project set-up. The third and final chapter focuses on the results of methods described in chapter 2, contains personal advice for future approaches for improving the algorithm’s results and discusses the results. The thesis provides the theory, code snippets for the most fundamental part of the algorithms’ implementations and shows graphical, as well as numerical results of the approaches.", month = aug, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Zusag-2017-Bach/", } @bachelorsthesis{stappen_2017_animatedcomic, title = "Hybrid Frames - Animated Narrative Sequences in Molecular Visualization", author = "Stefan Stappen", year = "2017", abstract = "In bio-molecular visualizations animations are used to convey transitions between different representation states. For example, to understand the transition from a physical correct representation of a HIV molecule to an abstract visualization like a bar chart, an animation can be used. This method allows to trace the structures during the transition and therefore brings them into a direct relation. The disadvantage of an animation is that the presented content is fleeting. Therefore, the change over time cannot be compared or investigated in detail. To mitigate this disadvantage, we propose a hybrid visualization composed of an animation and a series of still images. The series of still images allows an overview over the transition and comparison of states, but the relation of the representations may get lost. For this reason, the animation is used. By clicking on a single frame inside the sequence the animation is played starting from the selected frame to the next frame in the sequence. The expressiveness of the narrative sequence of images is determined by the selected images. Therefore, we adapted Key Probe, an object based key frame extraction method developed by Huang et al., to be operable on molecular data. Molecular data consists of thousands of protein instances and is therefore challenging for object based key frame extraction methods. We introduced several optimization techniques to Key Probe. We show that the adapted Key Probe returns reasonable result within a reasonable computation time. The so extracted key frames are then displayed in a sequence of images together with a 3D animated view of the molecular data. This allows, additionally to the fast overview, an in-depth exploration of a specific sub-sequence of the animation.", month = aug, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/stappen_2017_animatedcomic/", } @misc{Groeller-2017-PTPMD, title = "AnimoAminoMiner: Exploration of Protein Tunnels and their Properties in Molecular Dynamics", author = "Jan Byska and Mathieu Le Muzic and Eduard Gr\"{o}ller and Ivan Viola and Barbora Kozlikova", year = "2017", month = jul, event = "BioVis@ISMB 2017", Conference date = "Poster presented at BioVis@ISMB 2017 (2017-07-24)", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Groeller-2017-PTPMD/", } @mastersthesis{ERLER-2017-HVR, title = "Haptic Feedback in Room-Scale VR", author = "Philipp Erler", year = "2017", abstract = "Virtual reality (VR) is now becoming a mainstream medium. Current systems like the HTC Vive offer accurate tracking of the HMD and controllers, which allows for highly immersive interactions with the virtual environment. The interactions can be further enhanced by adding feedback. As an example, a controller can vibrate when it is close to a grabbable ball. As such interactions are not exhaustingly researched, we conducted a user study. Specifically, we examine: - grabbing and throwing with controllers in a simple basketball game. - the influence of haptic and optical feedback on performance, presence, task load, and usability. - the advantages of VR over desktop for point-cloud editing. Several new techniques emerged from the point-cloud editor for VR. The bi-manual pinch gesture, which extends the handlebar metaphor, is a novel viewing method used to translate, rotate, and scale the point-cloud. Our new rendering technique uses the geometry shader to draw sparse point clouds quickly. The selection volumes at the controllers are our new technique to efficiently select points in point clouds. The resulting selection is visualized in real time. The results of the user study show that: - grabbing with a controller button is intuitive but throwing is not. Releasing a button is a bad metaphor for releasing a grabbed virtual object in order to throw it. - any feedback is better than none. Adding haptic, optical, or both feedback types to the grabbing improves the user performance and presence. However, only sub-scores like accuracy and predictability are significantly improved. Usability and task load are mostly unaffected by feedback. - the point-cloud editing is significantly better in VR with the bi-manual pinch gesture and selection volumes than on the desktop with the orbiting camera and lasso selections. ", month = jul, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "virtual reality, room-scale VR, throwing, grabbing, physics, basketball, haptic feedback, optical feedback, controllers, point cloud, point-cloud editing, presence, performance, usability, task load", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/ERLER-2017-HVR/", } @talk{Purgathofer-2017-VC-Interface, title = "Visual Computing als Interface zur Entscheidungsunterst\"{u}tzung", author = "Werner Purgathofer", year = "2017", month = jul, event = "RailTec 4.0 Workshop", location = "Wien", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Purgathofer-2017-VC-Interface/", } @bachelorsthesis{Kovacs_2017, title = "Shadow Volumes in Unreal Engine 4", author = "B\'{a}lint Istvan Kov\'{a}cs", year = "2017", abstract = "The presented bachelor thesis project explores the possibilities of implementing custom lighting techniques in a state-of-the-art game engine. Specifically, Unreal Engine 4 is analyzed for the feasibility of implementing shadow volumes in a shader-centric plugin. The thesis discusses the theoretical and practical background of Unreal Engine and of shadow volumes, and provides detailed information on every implementation step. It shows the challenges of customization and the results achieved.", month = jun, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Kovacs_2017/", } @bachelorsthesis{Escribano_2017, title = "Visual Evaluation of Computational Models of the Biological Mesoscale", author = "Guillermo Garcia-Escribano", year = "2017", abstract = "Currently available techniques for capturing macromolecules on atomic level are not appropriate for large structures on the biological mesoscale. Therefore, those structures, such as viruses or cell organelles, have to be assembled from molecular building blocks using software tools. The goal of recent projects like cellPACK is to create models with these tools, allowing the scientific community to iteratively give feedback and edit the models, in order to eventually generate the most suitable illustration consistent with the current state of knowledge. For that purpose, we need to discern the values for properties like distribution, density or opacity that make a model preferable to others. This thesis aims to create a software program for visual evaluation of the quality of the assembled structures. The program will extract the information about the quality of spatial distribution of molecules in the scenes produced by packing tools and plot it into a set of 2D representations. These will convey the statistical information about the distribution and enable the visual comparison of generated models, which vary not only due to the stochastic nature of the packing algorithms but also because of the use of different parameter settings.", month = jun, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Escribano_2017/", } @article{CORNEL-2017-FRS, title = "Forced Random Sampling: fast generation of importance-guided blue-noise samples", author = "Daniel Cornel and Hiroyuki Sakai and Christian Luksch and Michael Wimmer", year = "2017", abstract = "In computer graphics, stochastic sampling is frequently used to efficiently approximate complex functions and integrals. The error of approximation can be reduced by distributing samples according to an importance function, but cannot be eliminated completely. To avoid visible artifacts, sample distributions are sought to be random, but spatially uniform, which is called blue-noise sampling. The generation of unbiased, importance-guided blue-noise samples is expensive and not feasible for real-time applications. Sampling algorithms for these applications focus on runtime performance at the cost of having weak blue-noise properties. Blue-noise distributions have also been proposed for digital halftoning in the form of precomputed dither matrices. Ordered dithering with such matrices allows to distribute dots with blue-noise properties according to a grayscale image. By the nature of ordered dithering, this process can be parallelized easily. We introduce a novel sampling method called forced random sampling that is based on forced random dithering, a variant of ordered dithering with blue noise. By shifting the main computational effort into the generation of a precomputed dither matrix, our sampling method runs efficiently on GPUs and allows real-time importance sampling with blue noise for a finite number of samples. We demonstrate the quality of our method in two different rendering applications.", month = jun, journal = "The Visual Computer", volume = "33", number = "6", issn = "1432-2315", pages = "833--843", keywords = "blue-noise sampling, importance sampling", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/CORNEL-2017-FRS/", } @inproceedings{geymayer-2017-std, title = "How Sensemaking Tools Influence Display Space Usage", author = "Thomas Geymayer and Manuela Waldner and Alexander Lex and Dieter Schmalstieg", year = "2017", abstract = "We explore how the availability of a sensemaking tool influences users’ knowledge externalization strategies. On a large display, users were asked to solve an intelligence analysis task with or without a bidirectionally linked concept-graph (BLC) to organize insights into concepts (nodes) and relations (edges). In BLC, both nodes and edges maintain “deep links” to the exact source phrases and sections in associated documents. In our control condition, we were able to reproduce previously described spatial organization behaviors using document windows on the large display. When using BLC, however, we found that analysts apply spatial organization to BLC nodes instead, use significantly less display space and have significantly fewer open windows.", month = jun, event = "EuroVis 2017", booktitle = "EuroVis Workshop on Visual Analytics", keywords = "sensemaking, large displays, evaluation", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/geymayer-2017-std/", } @mastersthesis{PODARAS-2017-ACRS, title = "Automated Classification of Road-Surface Types Based on Crowd-Sourced Data", author = "Silvana Podaras", year = "2017", abstract = "This thesis presents a method to automatically estimate road-surface types based on crowd-sourced and open source data to give cyclists an overview of the road conditions along a cycle route. Automatic classification of land-cover has been an active research field in recent years and mainly focuses on the classification of areas based on digital satellite and aerial imagery. Performing classification of road-surfaces based on such images bears some special challenges because roads have a width of only a few pixels on these photos, which makes it difficult to successfully apply classical image-analysis methods. Problems are caused by mixed pixels, which do not belong to a single surface class exclusively. Due to objects occluding the street, like for example trees and cars, it is difficult to isolate the street’s actual surface from the rest of the image. This biases the classification procedure and may cause faulty results. Furthermore, aerial images of high spatial resolution are only available with a small range of spectral bands. This thesis proposes an alternative approach for road-surface classification by utilizing open source data with a focus on data from the project OpenStreetMap (OSM). OSM is an online mapping project which collects geographical data and makes it available freely by providing a digital world map. Data is collected by users on a voluntary basis. OSM offers its users the possibility to add various properties to streets by making textual annotations. From these so-called tags it is possible to deduce road-surface properties for numerous roads by using methods from pattern recognition. The system is designed so it can be extended with additional data from other sources (e.g., height information) to improve classification results. Classification takes place at two levels, based on a coarse-to-fine-grained surface taxonomy. The method was evaluated on different testing areas in Austria and Liechtenstein. At the coarse-grained level, up to 90% of streets were correctly classified. At the fine-grained level, up to 60% of streets were correctly classified. The advantage of the proposed method is that it is fast and applicable to regions worldwide at low cost, as long as sufficient OSM data for a certain region is available.", month = may, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/PODARAS-2017-ACRS/", } @bachelorsthesis{Matusich-2017-01, title = "Billboarded Cutaway Visualization for Subsurface Urban Sewer Networks - Flood Simulation embedded in Unity3D", author = "Manuel Matusich", year = "2017", abstract = "Visualizing the results of a flood simulation interactively in real-time has become very important due to the increasing number of flood hazards in the recent past. An important part of a flood simulation is the impact on the sewer system of the flooded city. For the simulation itself only a very primitive data structure of a sewer system is required. Therefore this thesis proposes an innovative and efficient technique to render sewage pipes and to visualize the water flow inside of them. With a simple underlying data structure of node positions, billboarded sewage pipes are constructed in the geometry shader. With a proxy geometry the stencil buffer is utilized to distinguish outside and inside of the pipe and the billboards are drawn accordingly. In addition another technique is introduced to cut-open the occluding terrain to expose the sewage pipes to the viewer. Therefore a two dimensional distance transform of the sewer network is generated. The created distance field is used to discard fragments of the terrain, which are relatively close to a pipe. Further an artificial thickness is added to the cut-open terrain analytically in image-space. The techniques are presented in detail and their implementation is demonstrated in Unity3D. It is evaluated by comparing the result to multiple conventions for computer generated cutaways. Additionally the feedback from visualization experts and the technical performance is presented. The results show that billboarded and cut-open tubular geometry can be rendered fast, efficient and with a low memory footprint. Furthermore the technique fulfills many of the design principles for cutaways and got positive feedback from visualization experts.", month = may, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Matusich-2017-01/", } @inproceedings{Radwan-2017-Occ, title = "Cut and Paint: Occlusion-Aware Subset Selection for Surface Processing", author = "Mohamed Radwan and Stefan Ohrhallinger and Elmar Eisemann and Michael Wimmer", year = "2017", abstract = "User-guided surface selection operations are straightforward for visible regions on a convex model. However, concave surfaces present a challenge because self-occlusions require multiple camera positions to get unobstructed views. Therefore, users often have to locate and switch to new unobstructed views in order to continue the operation. Our novel approach enables operations like painting or cutting in a single view, even on the backside of objects and for arbitrary depth complexity, with interactive performance. Continuous projection of a curve drawn in screen space onto the mesh guarantees seamless brush strokes or manifold cuts, unaffected by any occlusions. Our occlusion-aware surface-processing method enables a number of applications in an easy way. As examples, we show continuous painting on the surface, selecting regions for texturing, creating illustrative cutaways from nested models and animation of cutaways.", month = may, publisher = "Canadian Human-Computer Communications Society / Soci{\'e}t{\'e} canadienne du dialogue humain-machine", location = "Edmonton, Alberta, CA", event = "Graphics Interface 2017", doi = "10.20380/GI2017.11", booktitle = "Proceedings of Graphics Interface 2017", pages = "82--89", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Radwan-2017-Occ/", } @inproceedings{waldner-2017-vph, title = "Exploring Visual Prominence of Multi-Channel Highlighting in Visualizations", author = "Manuela Waldner and Alexey Karimov and Eduard Gr\"{o}ller", year = "2017", abstract = "Visualizations make rich use of multiple visual channels so that there are few resources left to make selected focus elements visually distinct from their surrounding context. A large variety of highlighting techniques for visualizations has been presented in the past, but there has been little systematic evaluation of the design space of highlighting. We explore highlighting from the perspective of visual marks and channels – the basic building blocks of visualizations that are directly controlled by visualization designers. We present the results from two experiments, exploring the visual prominence of highlighted marks in scatterplots: First, using luminance as a single highlight channel, we found that visual prominence is mainly determined by the luminance difference between the focus mark and the brightest context mark. The brightness differences between context marks and the overall brightness level have negligible influence. Second, multi-channel highlighting using luminance and blur leads to a good trade-off between highlight effectiveness and aesthetics. From the results, we derive a simple highlight model to balance highlighting across multiple visual channels and focus and context marks, respectively.", month = may, booktitle = "Spring Conference on Computer Graphics 2017", keywords = "information visualization, highlighting, focus+context, visual prominence", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/waldner-2017-vph/", } @inproceedings{Ganuza-2017-IVCSGM, title = "Interactive Visual Categorization of Spinel-Group Minerals", author = " Mar\'{i}a Luj\'{a}n Ganuza and Gabriela Ferracutti and Maria Florencia Gargiulo and Silvia Castro and Ernesto Bjerg and Eduard Gr\"{o}ller and Kresimir Matkovic", year = "2017", abstract = "Spinel-group minerals are excellent indicators of geological environments and are of invaluable help in the search for mineral deposits of economic interest. The geologists analyze them by means of Barnes and Roeder’s contours. In this paper, we present a collection of novel, interactive methods, which assist geologists in the categorization of spinel-group minerals. We fully integrate Barnes and Roeder’s contours using a polygonal representation. This makes it possible to efficiently superimpose user-provided point data over the contours, and to automatically rank the contours based on the number of enclosed points. We also allow the expert to create contours for the user-provided point data. Once user contours are created, they can be compared with Barnes and Roeder’s contours. During the analysis, the user can drill-down by means of brushing. As we deal with specific data, we apply two novel brushing techniques, i.e., the percentile brush and the contour brush. The novel brushing mechanisms along with the interactive comparison speed-up the analysis significantly. We evaluate the newly introduced approach and the resulting novel workflow using real-word data from different locations in Argentina. According to the domain experts, the classification of spinel minerals needs several minutes now, while it took a few days with the current state of the art approach in the domain.", month = may, event = "33rd Spring Conference on Computer Graphics (SCCG 2017)", booktitle = "Proceedings of the 33rd Spring Conference on Computer Graphics (SCCG 2017)", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Ganuza-2017-IVCSGM/", } @inproceedings{Gehrer-2017-molmach, title = "Visualization of molecular machinery using agent-based animation", author = "Daniel Gehrer and Ivan Viola", year = "2017", month = may, event = "Spring Conference on Computer Graphics", booktitle = "Proceedings of SCCG 2017", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Gehrer-2017-molmach/", } @misc{kouril-2017-sccgposter, title = "Maya2cellVIEW: Integrated Tool for Creating Large and Complex Molecular Scenes", author = "David Kou\v{r}il and Mathieu Le Muzic and Barbora Kozlikova and Ivan Viola", year = "2017", month = may, event = "Spring Conference on Computer Graphics 2017", Conference date = "Poster presented at Spring Conference on Computer Graphics 2017 (2017-05)", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/kouril-2017-sccgposter/", } @inproceedings{sorger_2017_metamorphers, title = "Metamorphers: Storytelling Templates For Illustrative Animated Transitions in Molecular Visualization", author = "Johannes Sorger and Peter Mindek and Peter Rautek and Eduard Gr\"{o}ller and Graham Johnson and Ivan Viola", year = "2017", abstract = "In molecular biology, illustrative animations are used to convey complex biological phenomena to broad audiences. However, such animations have to be manually authored in 3D modeling software, a time consuming task that has to be repeated from scratch for every new data set, and requires a high level of expertise in illustration, animation, and biology. We therefore propose metamorphers: a set of operations for defining animation states as well as the transitions to them in the form of re-usable story telling templates. The re-usability is two-fold. Firstly, due to their modular nature, metamorphers can be re-used in different combinations to create a wide range of animations. Secondly, due to their abstract nature, metamorphers can be re-used to re-create an intended animation for a wide range of compatible data sets. Metamorphers thereby mask the low level complexity of explicit animation specifications by exploiting the inherent properties of the molecular data, such as the position, size, and hierarchy level of a semantic data subset.", month = may, location = "Mikulov, Czech Republic", booktitle = "Proceedings of the Spring Conference on Computer Graphics 2017", pages = "27--36", keywords = "animated transitions, storytelling, molecular visualization", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/sorger_2017_metamorphers/", } @article{Waldin_Nicholas_2017_FlickerObserver, title = "Flicker Observer Effect: Guiding Attention Through High Frequency Flicker in Images", author = "Nicholas Waldin and Manuela Waldner and Ivan Viola", year = "2017", abstract = "Drawing the user's gaze to an important item in an image or a graphical user interface is a common challenge. Usually, some form of highlighting is used, such as a clearly distinct color or a border around the item. Flicker can also be very salient, but is often perceived as annoying. In this paper, we explore high frequency flicker (60 to 72 Hz) to guide the user's attention in an image. At such high frequencies, the critical flicker frequency (CFF) threshold is reached, which makes the flicker appear to fuse into a stable signal. However, the CFF is not uniform across the visual field, but is higher in the peripheral vision at normal lighting conditions. Through experiments, we show that high frequency flicker can be easily detected by observers in the peripheral vision, but the signal is hardly visible in the foveal vision when users directly look at the flickering patch. We demonstrate that this property can be used to draw the user's attention to important image regions using a standard high refresh-rate computer monitor with minimal visible modifications to the image. In an uncalibrated visual search task, users could in a crowded image easily spot the specified search targets flickering with very high frequency. They also reported that high frequency flicker was distracting when they had to attend to another region, while it was hardly noticeable when looking at the flickering region itself.", month = may, journal = "Computer Graphics Forum", volume = "36", number = "2", pages = "467--476", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Waldin_Nicholas_2017_FlickerObserver/", } @bachelorsthesis{Balduz_01, title = "Walk line drawing", author = "Pablo Balduz", year = "2017", abstract = "In the recent years, consequence of technology improvements, a new kind of art has appeared. It is called GPS art and consists in drawing on a digital map by recording the path followed using a GPS device. The fact is that not everyone is able to make the drawing of a certain figure. Just the so-called GPS artists come up with the path, so it makes this kind of art not reachable to some people. The idea of this thesis is to enable people to create GPS art without relying on imagination to come up with a path for a certain figure. In order to achieve that, a system that finds that path in a map for a given figure as input has been developed. In order for people to use this system, it has been integrated within a mobile application, so users are able to find the path to follow easily. ", month = apr, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", keywords = "GPS art device", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Balduz_01/", } @mastersthesis{Gehrer-2017, title = "Visualization of molecular machinery using agent-based animation", author = "Daniel Gehrer", year = "2017", abstract = "This work proposes an agent-based model for animating molecular machines. Usually molecular machines are visualized using key-frame animation. Creating large molecular assemblies with key-frame animation in standard 3D software can be a tedious task, because hundreds or thousands of molecular particles have to be animated by hand, considering various biological phenomena. To avoid repetitive animation of molecular particles, a prototypic framework is implemented, that employs an agent-based approach. Instead of animating the molecular particles directly, the framework utilizes behavior descriptions for each type of molecular particle. The animation results from the molecular particles interacting with each other as defined by their behavior. Interaction between molecular particles is enabled by an abstract model that is implemented by the framework. The methodology for creating the framework was driven through learning by example. Three molecular machines are visualized using the framework. During this process, the framework was iteratively improved, to meet the requirements for each new molecular machine. The resulted animations demonstrate that agent-based animation is a viable option for molecular machines. ", month = apr, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Gehrer-2017/", } @bachelorsthesis{Mayr-2017-1, title = "Automatic Summarization of Image Datasets", author = "Patrick Mayr", year = "2017", abstract = "Since the innovation of the digital camera the number of pictures taken is still increasing. Especially in recent years, when mobile phone manufacturer began to attach digital cameras to their mobile phones, this ended up in a flood of pictures nowadays. The aim of this thesis is, to implement an algorithm that automatically summarizes a given dataset of geotagged images and creates a representative image collage. It is strictly based on the visualization pipeline and starts with the data analysis and filtering of the image dataset. Next, the filtered data are mapped using a symmetric version of the Voronoi tessellation, and are finally rendered using optional dissolve blending. We test the implementation on two different image datasets, containing 35 and 154 images, respectively. The results indicate that the implementation generates diverse and appealing image collages for the tested image datasets, but that there are also some extreme cases for example with misleading symmetry caused by the pre-attentive processing of the human visual system.", month = apr, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Mayr-2017-1/", } @bachelorsthesis{Winkler-2017, title = "Collaborative Procedural Modeling driven by User Feedback", author = "Andreas Winkler", year = "2017", abstract = "In this work a user centered procedural modeling framework is proposed which combines rule based content generation with the concepts of recommendation systems. Using the ACGAX modeling language, artists are able to write grammar scripts for the creation of diverse and complex 3D scenes, controlled with a simple goal notation. These scripts are evaluated and executed by the system to generate 3D-shapes using stored production rules from the cloud. The rule selection process is based on content based information filtering systems to create results matching the user’s preferences. User feedback is collected in a way that integrates explicit feedback into the modeling work flow via manual locking operations. These actions allow users to directly control the derivation process of grammars by fixing certain parts of the derivation tree. The goal of this research is not only to create a modeling tool, but a growing database of grammars, rules and feedback records. By observing how users interact with the grammars, the system learns which rules are most suitable for certain goals. The proposed system is designed to to learn from a user’s actions to improve the cloud based rule selection process for future modeling tasks.", month = apr, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Winkler-2017/", } @article{rraidou_EG17, title = "Visual Analytics for Digital Radiotherapy: Towards a Comprehensible Pipeline", author = "Renata Raidou and Marcel Breeuwer and Anna Vilanova i Bartroli", year = "2017", abstract = "Prostate cancer is one of the most frequently occurring types of cancer in males. It is often treated with radiation therapy,which aims at irradiating tumors with a high dose, while sparing the surrounding healthy tissues. In the course of the years,radiotherapy technology has undergone great advancements. However, tumors are not only different from each other, theyare also highly heterogeneous within, consisting of regions with distinct tissue characteristics, which should be treated withdifferent radiation doses. Tailoring radiotherapy planning to the specific needs and intra-tumor tissue characteristics of eachpatient is expected to lead to more effective treatment strategies. Currently, clinical research is moving towards this direction,but an understanding of the specific tumor characteristics of each patient, and the integration of all available knowledge into apersonalizable radiotherapy planning pipeline are still required. The present work describes solutions from the field of VisualAnalytics, which aim at incorporating the information from the distinct steps of the personalizable radiotherapy planningpipeline, along with eventual sources of uncertainty, into comprehensible visualizations. All proposed solutions are meantto increase the – up to now, limited – understanding and exploratory capabilities of clinical researchers. These approachescontribute towards the interactive exploration, visual analysis and understanding of the involved data and processes at differentsteps of the radiotherapy planning pipeline, creating a fertile ground for future research in radiotherapy planning.", month = apr, journal = "Computer Graphics Forum (Proceedings of Eurographics)", volume = "36", booktitle = "Computer Graphics Forum (Proceedings of Eurographics)", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/rraidou_EG17/", } @misc{mindek-2017-virtualcell, title = "The Birth of a Virtual Cell", author = "Peter Mindek and Johannes Sorger and David Kou\v{r}il and Tobias Klein and Graham Johnson and Ivan Viola", year = "2017", abstract = "In our current research project, we are working on the interactive visualization of cellular data at multiple scales. The visual story telling contest motivated us to describe the process of bringing this complex volumetric data "to life". We scripted the visual story directly within the current build of our multi-scale visualization. The entire video is therefore rendered in real time. This enabled us to directly show the steps involved in the rendering of our final visualization based on the actual data and the actual algorithms that are applied. The various effects in the video are therefore parameter variables for existing multi-scale visualization functions that change over time. The final result of our visualization was inspired by a rendering of the reference 3D model that was created by a scientific illustrator. The challenge that we overcome in our visualization was to create a rendering of the original data at stable 30 frames per second that matches the offline rendered illustration in visual quality, which helps to clarify the complex 3D arrangements of the inner components of the cell.", month = apr, note = "submitted to the Pacific Vis 2017 Storytelling Contest", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/mindek-2017-virtualcell/", } @bachelorsthesis{Mitterhofer_2017, title = "Modeling Microorganisms", author = "Lukas Mitterhofer", year = "2017", abstract = "Modeling of microorganisms is a cumbersome task, when biologists want to create a visual representation of a certain microorganism. To correctly model structures on atomic resolution, each molecule (for example proteins and lipids) has to be placed at its correct position. For microorganisms of larger dimensions the modeling process takes a very long time, at this point an improved modeling approach is required. It would be possible to create a rule-based modeling approach, but usually rules restrict the final outcome and produces repeating patterns. Therefore a tool that places molecules based on statistical evaluations and foresight was the main idea behind this project. The tool should allow for modeling complex organisms on molecular resolution by placing a minimal amount of examples and generalizing similar entities. A decision tree as learning structure evaluates the user’s actions, learns from them and reorganizes the whole structure. With this approach the user should be able to model complex cellular structures in as few steps as possible, also more complex actions, such as orientation towards a certain reference point, clusters, varying distribution united a real-time editor should improve the modeling task significantly.", month = mar, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Mitterhofer_2017/", } @bachelorsthesis{Gall_2017, title = "Comparison of Vessel Segmentation Techniques", author = "Alexander Gall", year = "2017", abstract = "Image segmentation is an important processing step in various applications and crucial in the medical field. When a new segmentation technique is introduced, validation and evaluation are essential for medical image analysis. But the automation of these processes is still not sufficient. Many algorithms have been published but there is still no satisfying way to assess whether an algorithm produces more accurate segmentations than another. More effort is spent on the development of algorithms than on their evaluation and therefore many researchers use the less complex subjective methods. For these techniques multiple experts are needed to visually compare several segmentation results, which is a very time-consuming process. Another way of comparing different results is the supervised evaluation method. Here we need experts, who manually segment reference images, which are used for comparison. As seen in recent researches there is a need for unsupervised methods due to many applications, in which user assistance is infeasible. The aim of this thesis is to provide an environment to visually and objectively evaluate segmentation results in the field of vessel segmentations. Our framework enables the comparison at voxel-level with various visualization techniques and objective measurements. These methods are meant to make the comparison more understandable for users. A subjective evaluation is realized through a comparative visualization by using a two- and three-dimensional comparison of voxels. Another general overview is provided by a maximum-intensity projection, which highlights the vessel structure. As purely objective evaluation technique, various metrics are used, to assure independence from experts or a ground truth. By using these techniques this paper presents an approach for evaluating differences in medical images, which does not rely on a permanent presence of an expert.", month = mar, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Gall_2017/", } @bachelorsthesis{Heim-2017, title = "Semiautomated Editing of Vessel Segmentation Masks", author = "Anja Heim", year = "2017", abstract = "This thesis describes a technique for editing segmentation results of vessels, which should enhance usage and reduce work duration for physicians by using a simple and fast way of interaction. Moreover also a quick calculation of an accurate result was of primary interest. Since vascular structures are vulnerable to diseases, vessels are the main focus of this thesis. Nowadays, Image Analysis is able to facilitate the medical diagnosis procedure. Since stroke treatment is time-crucial, appropriate algorithms should be fast and enable an accurate depiction of the arteries to simplify the diagnostic process. However, because automatic segmentation is often quite inaccurate and manual segmentation is tedious, neither of these two methods alone is often adequate for usage. Because of this we suggest to combine the fast automatic segmentation and the exact manual editing done by clinical experts. To reduce effort and working time of the medical staff, this thesis describes different techniques, which were developed to modify and, more importantly, to improve the segmentation results. The segmentation mask can be altered as its components can be separately removed and independent elements can be connected. A framework was implemented, with which a user is able to perform these tasks interactively. The deletion process is supported by various metrics, which enable the search and removal of similar structures. Also this framework assists the reconnection of vessels by finding the most likely connection by the means of image intensities and their gradients. The main goal of this thesis was to facilitate and accelerate the editing process by implementing fast semi-automatic algorithms. Intuitive interaction methods also had a major impact on the design.", month = mar, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Heim-2017/", } @bachelorsthesis{Wagner_032017, title = "3D-Printing of Fetal Ultrasound", author = "Julian Wagner", year = "2017", abstract = "3D printing has been used industrially for decades. It enables rapid prototyping while maintaining low costs. Personal 3D printing became popular approximately since 2011. Since the massive arise of public interest, 3D printers are getting more and more affordable. In this thesis, we show how fetal 3D ultrasound data can be processed to enable 3D printing. Major steps are classification of the tissues, extraction of the isosurface and mesh-smoothing. Our approach uses thresholding, in combination with Connected Component Analysis, to separate the mother tissues from the fetal tissues. From the labeled data, we extract the fetal surface using Marching Tetrahedra. The mesh is then smoothed and converted into a data format suitable for 3D printing. Depending on the quality of the given ultrasound data, we can generate a model with recognizable facial features and peripheral structures.", month = mar, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Wagner_032017/", } @article{birsak-2017-dpe, title = "Dynamic Path Exploration on Mobile Devices", author = "Michael Birsak and Przemyslaw Musialski and Peter Wonka and Michael Wimmer", year = "2018", abstract = "We present a novel framework for visualizing routes on mobile devices. Our framework is suitable for helping users explore their environment. First, given a starting point and a maximum route length, the system retrieves nearby points of interest (POIs). Second, we automatically compute an attractive walking path through the environment trying to pass by as many highly ranked POIs as possible. Third, we automatically compute a route visualization that shows the current user position, POI locations via pins, and detail lenses for more information about the POIs. The visualization is an animation of an orthographic map view that follows the current user position. We propose an optimization based on a binary integer program (BIP) that models multiple requirements for an effective placement of detail lenses. We show that our path computation method outperforms recently proposed methods and we evaluate the overall impact of our framework in two user studies.", month = may, doi = "10.1109/TVCG.2017.2690294", issn = "1077-2626", journal = "IEEE Transactions on Visualization and Computer Graphics", number = "5", volume = "24", pages = "1784--1798", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/birsak-2017-dpe/", } @bachelorsthesis{Wihann_2017, title = "Statistical Modelling of Microorganisms", author = "Theresa Wihann", year = "2017", abstract = "Models of a biological organism can support scientists in various fields, such as medicine, pharmacy or biology. When precise macromolecular composition of an organism is to be captured by the model, tens of thousands of protein macromolecules have to be positioned in order to create the model. This process is complicated and time consuming. In this thesis we propose an approach based on statistical modeling of microorganisms, which enables the creation of such scenes with minimal effort. The modeling is based on decision trees and probability calculations. The basic principle is to start with a random distribution. Then subsequently adjustments from the user on one or several objects, such as molecules, are gathered. These serve as examples to change the orientation and location of all other objects in the scene. The approach is realized in a tool implemented in Unity3D. ", month = feb, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Wihann_2017/", } @inproceedings{rao-2017-dc, title = "Damage characterization in SFRP using X-ray computed tomography after application of incremental and interrupted in situ quasi static tensile loading", author = "Guruprasad Rao and Aleksandr Amirkhanov and Dietmar Salaberger and Johannes Kastner and Christoph Heinzl", year = "2017", abstract = "The use of short fibre reinforced polymers (SFRP) is increasing steadily in automotive and aerospace industries due to its mechanical properties and light weight. The mechanical and physical properties of SFRP depend on the geometrical characterestics of the reinforcing material. Under tensile stress many defects are induced in SFRP composites. X-ray computed tomography (XCT) is a non-destructive method for damage characterization of SFRP. It helps us to understand the material behaviour under different intermediate stress conditions and gauge the strength of the material. This paper aims to study the evolution of various damages in SFRP composite material. The composite consists of a polyamide matrix and 30 wt. % of short glass fibres. Sheets with two types of fibre orientation (0° and 90°) were chosen relative to the flow direction. The damages were induced after application of pre-determined tensile loads in a quasi-static method using an in situ tensile testing device.The tensile force was applied using controlled displacement inside the in situ device. Damages were analysed after every step of force application using XCT at the resolution of 4.5 µm3 voxel size. The workflow based on automatic fibre extraction followed by automated defect detection and classification was used to retrieve quantitative results of the damage evolution. The detected defects were analysed and classified into four types: 1) fibre pull-outs, 2) fibre fractures, 3) matrix fractures and 4) fibre/matrix debonding. The increase in tensile force shows changes in the number and volume of the defects. The classification of defects at every step after applying force helps to understand evolution of damage mechanisms in the stressed region.", month = feb, booktitle = "Proceedings of 7th Conference on Industrial Computed Tomography , Leuven , Belgium (iCT 2017)", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/rao-2017-dc/", } @inproceedings{JAHRMANN-2017-RRTG, title = "Responsive Real-Time Grass Rendering for General 3D Scenes", author = "Klemens Jahrmann and Michael Wimmer", year = "2017", abstract = "Grass plays an important role in most natural environments. Most interactive applications use image-based techniques to approximate fields of grass due to the high geometrical complexity, leading to visual artifacts. In this paper, we propose a grass-rendering technique that is capable of drawing each blade of grass as geometrical object in real time. Accurate culling methods together with an adaptable rendering pipeline ensure that only the blades of grass that are important for the visual appearance of the field of grass are rendered. In addition, we introduce a physical model that is evaluated for each blade of grass. This enables that a blade of grass can react to its environment by calculating the influence of gravity, wind and collisions. A major advantage of our approach is that it can render fields of grass of arbitrary shape and spatial alignment. Thus, in contrast to previous work, the blades of grass can be placed on any 3D model, which is not required to be a flat surface or a height map.", month = feb, isbn = "978-1-4503-4886-7", publisher = "ACM", location = "San Francisco, CA", event = "I3D 2017", booktitle = "Proceedings of the 21st ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games", pages = "6:1--6:10", keywords = "real-time rendering, grass rendering, hardware tessellation", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/JAHRMANN-2017-RRTG/", } @inproceedings{SCHWAERZLER-2017-SBGM, title = "Sketch-based Guided Modeling of 3D Buildings from Oriented Photos", author = "Michael Schw\"{a}rzler and Lisa-Maria Kellner and Stefan Maierhofer and Michael Wimmer", year = "2017", abstract = "Capturing urban scenes using photogrammetric methods has become an interesting alternative to laser scanning in the past years. For the reconstruction of CAD-ready 3D models, two main types of interactive approaches have become prevalent: One uses the generated 3D point clouds to reconstruct polygonal surfaces, while the other focuses on 2D interaction in the photos to define edges and faces. We propose a novel interactive system that combines and enhances these approaches in order to optimize current reconstruction and modeling workflows. Our main interaction target are the photos, allowing simple 2D interactions and edge-based snapping. We use the underlying segmented point cloud to define the 3D context in which the sketched polygons are projected whenever possible. An intuitive visual guiding interface gives the user feedback on the accuracy to expect with the current state of modeling to keep the necessary interactions at a minimum level.", month = feb, isbn = "978-1-4503-4886-7", publisher = "ACM", location = "San Francisco, CA", event = "I3D 2017", booktitle = "Proceedings of the 21st ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games", pages = "9:1--9:8", keywords = "3D modeling, guidance, photogrammetry", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/SCHWAERZLER-2017-SBGM/", } @inproceedings{amirkhanov-2017-cffet, title = "Comparison of Final Fracture Extraction Techniques for Interrupted In situ Tensile Tests of Glass Fiber Reinforced Polymers", author = "Aleksandr Amirkhanov and Dietmar Salaberger and Johannes Kastner and Christoph Heinzl and Eduard Gr\"{o}ller", year = "2017", abstract = "To develop and optimize of advanced composite materials such as glass fiber reinforced polymers (GFRPs) for a specific application area is an important topic. To inspect mechanical properties of GFRPs, material engineers use interrupted in situ tensile tests. During these tests, a test specimen is scanned multiple times in an industrial computed tomography (CT) scanner under various loads, starting from no load until the final fracture of the specimen. In this work we focus on the final step of the interrupted in situ tensile test, which is scanned when the specimen is completely losing its structural integrity in the final fracture zone. The defects occurring in the subsequent loading stages merge and ultimately form the final fracture. For this reason, conventional techniques tend to generate error prone final fracture regions or surfaces and thus require more advanced algorithms for extraction. The main contribution of this paper is found in the comparison of different techniques for extracting the final fracture. In the comparison we outline advantages and drawbacks of the presented techniques relative to each other.", month = feb, booktitle = "Proceedings of 7th Conference on Industrial Computed Tomography , Leuven , Belgium (iCT 2017) ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/amirkhanov-2017-cffet/", } @bachelorsthesis{Eckelt_2017, title = "Vascular Printing - 3D Printing of Aortic Dissections", author = "Klaus Eckelt", year = "2017", month = jan, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Eckelt_2017/", } @WorkshopTalk{Groeller-2017-IVAMCS, title = "Interactive Visual Analysis in the Material and Computational Sciences", author = "Eduard Gr\"{o}ller", year = "2017", abstract = "Visualization and visual computing use computer-supported, interactive, visual representations of (abstract) data to amplify cognition. In recent years data complexity concerning volume, veracity, velocity, and variety has increased considerably. This is due to new data sources as well as the availability of uncertainty, error and tolerance information. Instead of individual objects entire sets, collections, and ensembles are visually investigated. There is a need for visual analyses, comparative visualization, quantitative visualizations, and scalable visualizations. The simultaneous exploration and visualization of spatial and abstract information is an important case in point. Several examples from the material and computational sciences will be discussed in detail. Given the amplified data variability, interactive visual data analyses are likely to gain in importance in the future. Research challenges and directions are sketched at the end of the talk. ", month = jan, event = "Workshop on Visual analysis of dynamic processes", location = "Rigi Kulm, Switzerland", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Groeller-2017-IVAMCS/", } @article{Kolesar-Fractional-2016, title = "A Fractional Cartesian Composition Model for Semi-Spatial ComparativeVisualization Design", author = "Ivan Koles\'{a}r and Stefan Bruckner and Ivan Viola and Helwig Hauser", year = "2017", month = jan, journal = "IEEE Transactions on Visualization and Computer Graphics", volume = "23", number = "1", doi = "10.1109/TVCG.2016.2598870", pages = "851-860", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Kolesar-Fractional-2016/", } @mastersthesis{Walch-2017-DA, title = "Lens Flare Prediction based on Measurements with Real-Time Visualization", author = "Andreas Walch", year = "2017", abstract = "Lens flare is a visual phenomenon caused by interreflection of light within a lens system. This effect is often undesired, but it gives rendered images a realistic appearance. In the area of computer graphics, several simulation based approaches have been presented to render lens flare for a given spherical lens system. An accurate model of the lens system and all its components is crucial for a physically reliable result. Since the effect differs from camera to camera, these methods are not flexible, and the internal parameters – especially the anti-reflection coatings – can only be approximated. In this thesis we present a novel workflow for generating physically plausible renderings of lens flare phenomena by analyzing the lens flares captured on a camera. Furthermore, our method allows to predict the occurrence of lens flares for a given light setup. This is an often requested feature in light planning applications in order to efficiently avoid lens flare prone light positioning. A model with a tight parameter set and a GPU-based rendering method allows our method to be used in real-time applications.", month = mar, address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Walch-2017-DA/", } @article{klein_2017_IM, title = "Instant Construction and Visualization of Crowded Biological Environments", author = "Tobias Klein and Ludovic Autin and Barbora Kozlikova and David Goodsell and Arthur Olson and Eduard Gr\"{o}ller and Ivan Viola", year = "2018", abstract = "We present the first approach to integrative structural modeling of the biological mesoscale within an interactive visual environment. These complex models can comprise up to millions of molecules with defined atomic structures, locations, and interactions. Their construction has previously been attempted only within a non-visual and non-interactive environment. Our solution unites the modeling and visualization aspect, enabling interactive construction of atomic resolution mesoscale models of large portions of a cell. We present a novel set of GPU algorithms that build the basis for the rapid construction of complex biological structures. These structures consist of multiple membrane-enclosed compartments including both soluble molecules and fibrous structures. The compartments are defined using volume voxelization of triangulated meshes. For membranes, we present an extension of the Wang Tile concept that populates the bilayer with individual lipids. Soluble molecules are populated within compartments using the Halton sequence for their distribution. Fibrous structures, such as RNA or actin filaments, are created by self-avoiding random walks. Resulting overlaps of molecules are resolved by a forced-based system. Our approach opens new possibilities to the world of interactive construction of cellular compartments. We demonstrate its effectiveness by showcasing scenes of different scale and complexity that comprise blood plasma, mycoplasma, and HIV.", journal = "IEEE Transactions on Visualization and Computer Graphics", doi = "10.1109/TVCG.2017.2744258", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/klein_2017_IM/", } @article{miao_tvcg_2017, title = "Placenta Maps: In Utero Placental Health Assessment of the Human Fetus", author = "Haichao Miao and Gabriel Mistelbauer and Alexey Karimov and Amir Alansary and Alice Davidson and David F.A. Lloyd and Mellisa Damodaram and Lisa Story and Jana Hutter and Joseph V. Hajnal and Mary Rutherford and Bernhard Preim and Bernhard Kainz and Eduard Gr\"{o}ller", year = "2017", abstract = "null", journal = "IEEE Transactions on Visualization and Computer Graphics", volume = "23", number = "6", pages = "1612--1623", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/miao_tvcg_2017/", } @article{HECHER-2017-HDY, title = "How Do Users Map Points Between Dissimilar Shapes?", author = "Michael Hecher and Paul Guerrero and Peter Wonka and Michael Wimmer", year = "2018", abstract = "Finding similar points in globally or locally similar shapes has been studied extensively through the use of various point descriptors or shape-matching methods. However, little work exists on finding similar points in dissimilar shapes. In this paper, we present the results of a study where users were given two dissimilar two-dimensional shapes and asked to map a given point in the first shape to the point in the second shape they consider most similar. We find that user mappings in this study correlate strongly with simple geometric relationships between points and shapes. To predict the probability distribution of user mappings between any pair of simple two-dimensional shapes, two distinct statistical models are defined using these relationships. We perform a thorough validation of the accuracy of these predictions and compare our models qualitatively and quantitatively to well-known shape-matching methods. Using our predictive models, we propose an approach to map objects or procedural content between different shapes in different design scenarios.", month = aug, doi = "10.1109/TVCG.2017.2730877", issn = "1077-2626", journal = "IEEE Transactions on Visualization and Computer Graphics", number = "8", volume = "24", pages = "2327--2338", keywords = "shape matching, transformations, shape similarity", URL = "https://www.cg.tuwien.ac.at/research/publications/2018/HECHER-2017-HDY/", } @talk{miao_inria_2017, title = "Visualization and Modeling in DNA Nanotechnology", author = "Haichao Miao", year = "2017", month = apr, event = "Inria", location = "Inria, Grenoble, France", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/miao_inria_2017/", } @bachelorsthesis{mazurek-2017-sio, title = "Stream I/O - An Interactive Visualization of Publication Data", author = "Michael Mazurek", year = "2017", abstract = "The publication database of the Institute of Computer Graphics and Algorithms can currently be queried by a simple UI which returns a list. Stream I/O, the application of this thesis, extends the interface to improve it in terms of overview, exploration and analysis support. To cope with these shortcommings a visualization is added to the user interface. As the publication database includes a lot of additional data attributes, a selection of attributes is used for the visualization to give further insight. By using the Streamgraph [BW08] visualization, the variations over time within attributes like authors, publication type and research areas are made visible. The focus of this visualization lies in showing individual attribute values while also conveying the sum. This relationship is depicted in a timeline, which allows a user to explore the past and current work of the institute as well as to find relationships and trends in the publications. As the visualization uses a timeline encoding, the directed flow from left to right is interpreted as the movement through time. It shows the evolution of different attributes, while the occurrence of a topic at a specific time is coded with the width of the layer at a specific point. Searching the database is enriched through multiple viewpoints which give the user insight how attributes relate in the underlying data and how the data is changing through his/her manipulation. Selections of colored layers within the graph can represent bigger trends and give insight into the data as a whole. The Stream I/O application invites users to interactively explore the publication database, while simultaneously gaining new insight through the visualization.", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/mazurek-2017-sio/", } @studentproject{mazurek-2017-vows, title = "Visualization of Thesaurus-Based Web Search", author = "Michael Mazurek", year = "2017", abstract = "The general functions of current web search engines are well established. A box is provided in which to type the queries and the engine returns a result list which users can evaluate. The autocomplete suggestions assist users in defining their problems, however there is a lack of support for an iterative manual refinement of the query. This additional aid can be beneficial when users not know the exact terms to describe the concept they are looking for. Therefore, the goal of this project is to show searchers how a slight variation of the query changes the results. With this information, they then can perform a targeted refinement of the query to access useful information sources. To achieve this goal, each part of the searcher’s query is varied with a thesaurus that provides synonyms for the individual query terms. While performing the user’s original query in a normal fashion, variations of this query are conducted in the background. To provide a concise visual summary of the query results, text mining techniques are performed on all gathered results to retrieve the most important key terms for each query variation. This procedure results in a visual overview of what the searcher’s query finds together with what could be found with a slight variation of the query. Additional queries should make users aware that alternative queries may be more appropriate when their original query is poorly formulated. In conjunction with some interaction tools, the goal is to reduce the burden of refining search queries and therefore making searching the web less complex.", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/mazurek-2017-vows/", } @article{mindek-2017-marion, title = "Visualization Multi-Pipeline for Communicating Biology", author = "Peter Mindek and David Kou\v{r}il and Johannes Sorger and David Toloudis and Blair Lyons and Graham Johnson and Eduard Gr\"{o}ller and Ivan Viola", year = "2017", abstract = "We propose a system to facilitate biology communication by developing a pipeline to support the instructional visualization of heterogeneous biological data on heterogeneous user-devices. Discoveries and concepts in biology are typically summarized with illustrations assembled manually from the interpretation and application of heterogenous data. The creation of such illustrations is time consuming, which makes it incompatible with frequent updates to the measured data as new discoveries are made. Illustrations are typically non-interactive, and when an illustration is updated, it still has to reach the user. Our system is designed to overcome these three obstacles. It supports the integration of heterogeneous datasets, reflecting the knowledge that is gained from different data sources in biology. After pre-processing the datasets, the system transforms them into visual representations as inspired by scientific illustrations. As opposed to traditional scientific illustration these representations are generated in real-time - they are interactive. The code generating the visualizations can be embedded in various software environments. To demonstrate this, we implemented both a desktop application and a remote-rendering server in which the pipeline is embedded. The remote-rendering server supports multi-threaded rendering and it is able to handle multiple users simultaneously. This scalability to different hardware environments, including multi-GPU setups, makes our system useful for efficient public dissemination of biological discoveries. ", journal = "IEEE Transactions on Visualization and Computer Graphics", volume = "24", number = "1", keywords = "Biological visualization, remote rendering, public dissemination", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/mindek-2017-marion/", } @bachelorsthesis{travnicek-2017-thm, title = "Tangible Historical Maps: An Approach Towards Customisable 3D Printed Historical Maps", author = "Tanja Travnicek", year = "2017", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/travnicek-2017-thm/", } @bachelorsthesis{Koszticsak-2017-ewt, title = "Generating Expressive Window Thumbnails through Seam Carving", author = "Rebeka Koszticsak", year = "2017", abstract = "Thumbnails are used to display lists of open windows or tabs when switching between them on computers and on mobile devices. These images make it easier to recognize the opened applications, and help to find the needed window quicker. Thumbnails however only display a screenshot of the windows, so they get potentially confusing if there are more opened windows or if the same application is opened multiple times. Depending on the resolution of the display, the screenshot size decreases as the number of opened windows increases. Furthermore, within the same application (like MS Office World) the screenshots are similar in appearance (e.g. : white paper and tool bar), but the important text is not readable. There are several approaches that filter the important areas of the images to enhance the main region. In this bachelor thesis an application is implemented that uses the above methods on screenshots. Screenshots of windows are reduced by cropping the irrelevant elements of the margin area using seam carving, i.e. by eliminating the non-important pixel paths; and by common down-sampling. As a result the thumbnails show only relevant information, which makes them more expressive and easier to fulfill their purpose.", address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria", school = "Institute of Computer Graphics and Algorithms, Vienna University of Technology ", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Koszticsak-2017-ewt/", } @inproceedings{vad_viktor-2017-WVE, title = "Watergate: Visual Exploration of Water Trajectories in Protein Dynamics", author = "Viktor Vad and Jan Byska and Adam Jurcik and Ivan Viola and Eduard Gr\"{o}ller and Helwig Hauser and Sergio M. Margues and Jiri Damborsky and Barbora Kozlikova", year = "2017", abstract = "The function of proteins is tightly related to their interactions with other molecules. The study of such interactions often requires to track the molecules that enter or exit specific regions of the proteins. This is investigated with molecular dynamics simulations, producing the trajectories of thousands of water molecules during hundreds of thousands of time steps. To ease the exploration of such rich spatio-temporal data, we propose a novel workflow for the analysis and visualization of large sets of water-molecule trajectories. Our solution consists of a set of visualization techniques, which help biochemists to classify, cluster, and filter the trajectories and to explore the properties and behavior of selected subsets in detail. Initially, we use an interactive histogram and a time-line visualization to give an overview of all water trajectories and select the interesting ones for further investigation. Further, we depict clusters of trajectories in a novel 2D representation illustrating the flows of water molecules. These views are interactively linked with a 3D representation where we show individual paths, including their simplification, as well as extracted statistical information displayed by isosurfaces. The proposed solution has been designed in tight collaboration with experts to support specific tasks in their scientific workflows. They also conducted several case studies to evaluate the usability and effectiveness of our new solution with respect to their research scenarios. These confirmed that our proposed solution helps in analyzing water trajectories and in extracting the essential information out of the large amount of input data.", location = "September, 2017 Bremen, Germany", booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine 2017", pages = "33--42", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/vad_viktor-2017-WVE/", } @incollection{SCHEIBLAUER-2015-WFC, title = "Workflow for Creating and Rendering Huge Point Models", author = "Claus Scheiblauer and Norbert Zimmermann and Michael Wimmer", year = "2017", booktitle = "Fundamentals of Virtual Archaeology: Theory and Practice", isbn = "9781466594760", note = "(to appear) 15.06.2017", publisher = "A K Peters/CRC Press", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/SCHEIBLAUER-2015-WFC/", } @article{Viola-Pondering-2017, title = "Pondering the Concept of Abstraction in (Illustrative) Visualization", author = "Ivan Viola and Tobias Isenberg", year = "2017", abstract = "We explore the concept of abstraction as it is used in visualization, with the ultimate goal of understanding and formally defining it. Researchers so far have used the concept of abstraction largely by intuition without a precise meaning. This lack of specificity left questions on the characteristics of abstraction, its variants, its control, or its ultimate potential for visualization and, in particular, illustrative visualization mostly unanswered. In this paper we thus provide a first formalization of the abstraction concept and discuss how this formalization affects the application of abstraction in a variety of visualization scenarios. Based on this discussion, we derive a number of open questions still waiting to be answered, thus formulating a research agenda for the use of abstraction for the visual representation and exploration of data. This paper, therefore, is intended to provide a contribution to the discussion of the theoretical foundations of our field, rather than attempting to provide a completed and final theory.", month = sep, journal = "IEEE Transactions on Visualization and Computer Graphics", number = "99", doi = "10.1109/TVCG.2017.2747545", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/Viola-Pondering-2017/", } @studentproject{steinboeck-2017-vefp, title = "Visualization of EU Funding Programmes", author = "Daniel Steinb\"{o}ck", year = "2017", abstract = "To fund research and technological development, not only in Europe but all over the world, the European Union created so-called Framework Programmes. The data of these programmes, containing information about projects, corresponding topics, funding sums, funding periods and recipient countries, is publicly available, but hard to analyze without visual support. Therefore, a multiple coordinated view approach is developed in course of this project. The different visualization techniques used, like bar charts, treemap, choropleth map and line graph, make it possible to filter, analyze and further explore the available data through brushing and linking. The project was developed in close collaboration with the end users of the Centre for Social Innovation and received an overall positive feedback from them.", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/steinboeck-2017-vefp/", } @talk{miao_stateKeylabTalk_2017, title = "Visualization of Brain Arteries, the Placenta and DNA Nanostructures in the Context of Abstraction", author = "Haichao Miao", year = "2017", event = "State Key Lab - Zhejiang University", location = "State Key Lab - Zhejiang University", URL = "https://www.cg.tuwien.ac.at/research/publications/2017/miao_stateKeylabTalk_2017/", }