EDBT 2026 Demo / reviewers in the wild / expert
Pere-Pau Vázquez
dblp:84/368 · also Pere-Pau Vázquez Alcocer
· DBLP profile ↗
43ranked-venue papers
10as first author
14since 2021 · last 2026
0000-0003-4638-4065ORCID · verified
Domains — the database's venue-derived domains; a paper can count in several
Graphics, computer vision, multimedia, augmented reality and games · 36 · 6 first-author · 12 since 2021Human-computer interaction and ubiquitous computing · 3 · 1 first-author · 1 since 2021Applied, interdisciplinary, general and emerging computing · 3 · 2 first-authorArtificial intelligence and machine learning · 2 · 2 since 2021Systems, architecture and hardware · 1 · 1 first-authorDatabases, data management, data science and information retrieval · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | PaCoNet: Deep Data Extraction for Parallel Coordinates
Poonam Poonam, Hannah Kniesel, Pere-Pau Vázquez, Timo Ropinski |
ICPR (11) | 3 |
| 2026 | Evaluating LLMs' abilities to create charts, a systematic approachabstractThe use of generative models, especially those based on pretrained transformers, has become a common practice in code development. Tools such as GitHub Copilot, Cursor, and the direct use of conversational chatbots have proven useful to accelerate the development of applications. Unfortunately, generative models are unable to determine what is correct or wrong, and their outputs may contain errors. Their stochastic nature does not guarantee a single solution for the same problem, either. Furthermore, the output depends largely on the prompt issued by the user. To assess the capabilities of LLMs, some benchmarks have been proposed. Unfortunately, they often rely on ground truth data that may not be available. As a result, the extent to which modern LLMs can create charts needs further investigation. This work contributes to the understanding of the generative models’ ability to create charts in three ways: (a) Creating a dataset of prompts, data sources, and chart types to analyze, (b) Designing a set of systematic experiments that cover a wide range of commonly used charts, and variations of the visual variables, and (c) by empirically analyzing the performance of a large set of LLMs of different sizes, including Claude, CodeLlama, Gemini, Gemma, GPT4o, Llama 3.1, and Mixtral. Our results indicate that even the most advanced LLMs have room for improvement. Maria Ribalta-Albado, Pere-Pau Vázquez |
Comput. Graph. | 2 |
| 2025 | Evaluating graphical perception capabilities of Vision TransformersabstractVision Transformers (ViTs) have emerged as a powerful alternative to convolutional neural networks (CNNs) in a variety of image-based tasks. While CNNs have previously been evaluated for their ability to perform graphical perception tasks, which are essential for interpreting visualizations, the perceptual capabilities of ViTs remain largely unexplored. In this work, we investigate the performance of ViTs in elementary visual judgment tasks inspired by Cleveland and McGill’s foundational studies, which quantified the accuracy of human perception across different visual encodings. Inspired by their study, we benchmark ViTs against CNNs and human participants in a series of controlled graphical perception tasks. Our results reveal that, although ViTs demonstrate strong performance in general vision tasks, their alignment with human-like graphical perception in the visualization domain is limited. This study highlights key perceptual gaps and points to important considerations for the application of ViTs in visualization systems and graphical perceptual modeling. • We present the first evaluation of three canonical ViT architectures on low-level visual tasks, replicating and extending on the perception experiments conducted by Cleveland and McGill. • We compare ViTs performance to that of CNNs and human observers, and discuss the implications for perceptual alignment in visualization systems. Poonam Poonam, Pere-Pau Vázquez, Timo Ropinski |
Comput. Graph. | 2 |
| 2024 | Are LLMs ready for Visualization?abstractGenerative models have received a lot of attention in many areas of academia and the industry. Their capabilities span many areas, from the invention of images given a prompt to the generation of concrete code to solve a certain programming issue. These two paradigmatic cases fall within two distinct categories of requirements, ranging from "creativity" to "precision", as characterized by Bing Chat, which employs ChatGPT-4 as its backbone. Visualization practitioners and researchers have wondered to what end one of such systems could accomplish our work in a more efficient way. Several works in the literature have utilized them for the creation of visualizations. And some tools such as Lida, incorporate them as part of their pipeline. Nevertheless, to the authors’ knowledge, no systematic approach for testing their capabilities has been published, which includes both extensive and in-depth evaluation. Our goal is to fill that gap with a systematic approach that analyzes three elements: whether Large Language Models are capable of correctly generating a large variety of charts, what libraries they can deal with effectively, and how far we can go to configure individual charts. To achieve this objective, we initially selected a diverse set of charts, which are commonly utilized in data visualization. We then developed a set of generic prompts that could be used to generate them, and analyzed the performance of different LLMs and libraries. The results include both the set of prompts and the data sources, as well as an analysis of the performance with different configurations. Pere-Pau Vázquez |
PacificVis | 1 |
| 2024 | Virtual reality inspection of chromatin 3D and 2D dataabstractInternational audience Elena Molina, David Kouril, Tobias Isenberg 0001, Barbora Kozlíková, Pere-Pau Vázquez |
Comput. Graph. | 5 |
| 2023 | State of the Art of Molecular Visualization in Immersive Virtual EnvironmentsabstractAbstract Visualization plays a crucial role in molecular and structural biology. It has been successfully applied to a variety of tasks, including structural analysis and interactive drug design. While some of the challenges in this area can be overcome with more advanced visualization and interaction techniques, others are challenging primarily due to the limitations of the hardware devices used to interact with the visualized content. Consequently, visualization researchers are increasingly trying to take advantage of new technologies to facilitate the work of domain scientists. Some typical problems associated with classic 2D interfaces, such as regular desktop computers, are a lack of natural spatial understanding and interaction, and a limited field of view. These problems could be solved by immersive virtual environments and corresponding hardware, such as virtual reality head‐mounted displays. Thus, researchers are investigating the potential of immersive virtual environments in the field of molecular visualization. There is already a body of work ranging from educational approaches to protein visualization to applications for collaborative drug design. This review focuses on molecular visualization in immersive virtual environments as a whole, aiming to cover this area comprehensively. We divide the existing papers into different groups based on their application areas, and types of tasks performed. Furthermore, we also include a list of available software tools. We conclude the report with a discussion of potential future research on molecular visualization in immersive environments. David Kuták, Pere-Pau Vázquez, Tobias Isenberg 0001, Michael Krone, Marc Baaden, Jan Byska, Barbora Kozlíková, Haichao Miao |
Comput. Graph. Forum | 2 |
| 2023 | Two-step techniques for accurate selection of small elements in VR environmentsabstractOne of the key interactions in 3D environments is target acquisition, which can be challenging when targets are small or in cluttered scenes. Here, incorrect elements may be selected, leading to frustration and wasted time. The accuracy is further hindered by the physical act of selection itself, typically involving pressing a button. This action reduces stability, increasing the likelihood of erroneous target acquisition. We focused on molecular visualization and on the challenge of selecting atoms, rendered as small spheres. We present two techniques that improve upon previous progressive selection techniques. They facilitate the acquisition of neighbors after an initial selection, providing a more comfortable experience compared to using classical ray-based selection, particularly with occluded elements. We conducted a pilot study followed by two formal user studies. The results indicated that our approaches were highly appreciated by the participants. These techniques could be suitable for other crowded environments as well. Elena Molina, Pere-Pau Vázquez |
Graph. Model. | 2 |
| 2023 | Out of the Plane: Flower versus Star Glyphs to Support High-Dimensional Exploration in Two-Dimensional EmbeddingsabstractExploring high-dimensional data is a common task in many scientific disciplines. To address this task, two-dimensional embeddings, such as tSNE and UMAP, are widely used. While these determine the 2D position of data items, effectively encoding the first two dimensions, suitable visual encodings can be employed to communicate higher-dimensional features. To investigate such encodings, we have evaluated two commonly used glyph types, namely flower glyphs and star glyphs. To evaluate their capabilities for communicating higher-dimensional features in two-dimensional embeddings, we ran a large set of crowd-sourced user studies using real-world data obtained from data.gov. During these studies, participants completed a broad set of relevant tasks derived from related research. This article describes the evaluated glyph designs, details our tasks, and the quantitative study setup before discussing the results. Finally, we will present insights and provide guidance on the choice of glyph encodings when exploring high-dimensional data. Christian van Onzenoodt, Pere-Pau Vázquez, Timo Ropinski |
IEEE Trans. Vis. Comput. Graph. | 2 |
| 2022 | A visual tool for the analysis of usage trends of small and medium bicycle sharing systemsabstractThe last two decades have exhibited a profound transformation of traditional urban mobility patterns partly due to the exponential growth in both number and popularity of public bicycle sharing systems (BSS). Analysis and visualization of the data generated by BSSs have become of special interest to municipalities to evaluate the effect of their mobility programs and offer integrated urban mobility solutions. In this paper, we present a visualization system that aims to assist city officials from small and medium cities in their decision-making process with an intuitive representation of BSS’ data. It has been developed, tested, and evaluated together with officials and domain experts from the city of Logroño (Spain). Our tool presents usage information with different time granularities (yearly, monthly, weekly, or seasonally), shows traffic flows between stations, and provides an in-depth breakdown of users’ data such as their registered address, traveled distance, or gender-based patterns. Alexandra Cortez-Ordoñez, José Antonio Sanchez-Espigares, Pere-Pau Vázquez |
Comput. Graph. | 3 |
| 2022 | Learning Human Viewpoint Preferences from Sparsely Annotated ModelsabstractAbstract View quality measures compute scores for given views and are used to determine an optimal view in viewpoint selection tasks. Unfortunately, despite the wide adoption of these measures, they are rather based on computational quantities, such as entropy, than human preferences. To instead tailor viewpoint measures towards humans, view quality measures need to be able to capture human viewpoint preferences. Therefore, we introduce a large‐scale crowdsourced data set, which contains 58k annotated viewpoints for 3220 ModelNet40 models. Based on this data, we derive a neural view quality measure abiding to human preferences. We further demonstrate that this view quality measure not only generalizes to models unseen during training, but also to unseen model categories. We are thus able to predict view qualities for single images, and directly predict human preferred viewpoints for 3D models by exploiting point‐based learning technology, without requiring to generate intermediate images or sampling the view sphere. We will detail our data collection procedure, describe the data analysis and model training and will evaluate the predictive quality of our trained viewpoint measure on unseen models and categories. To our knowledge, this is the first deep learning approach to predict a view quality measure solely based on human preferences. Sebastian Hartwig, Michael Schelling, Christian van Onzenoodt, Pere-Pau Vázquez, Pedro Hermosilla, Timo Ropinski |
Comput. Graph. Forum | 4 |
| 2021 | Intrinsic-Extrinsic Convolution and Pooling for Learning on 3D Protein Structures
Pedro Hermosilla, Marco Schäfer, Matej Lang, Gloria Fackelmann, Pere-Pau Vázquez, Barbora Kozlíková, Michael Krone, Tobias Ritschel 0001, Timo Ropinski |
ICLR | 5 |
| 2021 | TourVis: Narrative Visualization of Multi-Stage Bicycle RacesabstractAbstract There are many multiple‐stage racing competitions in various sports such as swimming, running, or cycling. The wide availability of affordable tracking devices facilitates monitoring the position along with the race of all participants, even for non‐professional contests. Getting real‐time information of contenders is useful but also unleashes the possibility of creating more complex visualization systems that ease the understanding of the behavior of all participants during a simple stage or throughout the whole competition. In this paper we focus on bicycle races, which are highly popular, especially in Europe, being the Tour de France its greatest exponent. Current visualizations from TV broadcasting or real‐time tracking websites are useful to understand the current stage status, up to a certain extent. Unfortunately, still no current system exists that visualizes a whole multi‐stage contest in such a way that users can interactively explore the relevant events of a single stage (e.g. breakaways, groups, virtual leadership…), as well as the full competition. In this paper, we present an interactive system that is useful both for aficionados and professionals to visually analyze the development of multi‐stage cycling competitions. José Díaz 0003, Marta Fort, Pere-Pau Vázquez |
Comput. Graph. Forum | 3 |
| 2021 | Visual Analysis of Large-Scale Protein-Ligand Interaction DataabstractAbstract When studying protein‐ligand interactions, many different factors can influence the behaviour of the protein as well as the ligands. Molecular visualisation tools typically concentrate on the movement of single ligand molecules; however, viewing only one molecule can merely provide a hint of the overall behaviour of the system. To tackle this issue, we do not focus on the visualisation of the local actions of individual ligand molecules but on the influence of a protein and their overall movement. Since the simulations required to study these problems can have millions of time steps, our presented system decouples visualisation and data preprocessing: our preprocessing pipeline aggregates the movement of ligand molecules relative to a receptor protein. For data analysis, we present a web‐based visualisation application that combines multiple linked 2D and 3D views that display the previously calculated data The central view, a novel enhanced sequence diagram that shows the calculated values, is linked to a traditional surface visualisation of the protein. This results in an interactive visualisation that is independent of the size of the underlying data, since the memory footprint of the aggregated data for visualisation is constant and very low, even if the raw input consisted of several terabytes. Karsten Schatz, Juan José Franco-Moreno, Marco Schäfer, Alexander S. Rose, Valerio Ferrario, Jürgen Pleiss, Pere-Pau Vázquez, Thomas Ertl, Michael Krone |
Comput. Graph. Forum | 7 |
| 2021 | Enabling Viewpoint Learning through Dynamic Label GenerationabstractAbstract Optimal viewpoint prediction is an essential task in many computer graphics applications. Unfortunately, common viewpoint qualities suffer from two major drawbacks: dependency on clean surface meshes, which are not always available, and the lack of closed‐form expressions, which requires a costly search involving rendering. To overcome these limitations we propose to separate viewpoint selection from rendering through an end‐to‐end learning approach, whereby we reduce the influence of the mesh quality by predicting viewpoints from unstructured point clouds instead of polygonal meshes. While this makes our approach insensitive to the mesh discretization during evaluation, it only becomes possible when resolving label ambiguities that arise in this context. Therefore, we additionally propose to incorporate the label generation into the training procedure, making the label decision adaptive to the current network predictions. We show how our proposed approach allows for learning viewpoint predictions for models from different object categories and for different viewpoint qualities. Additionally, we show that prediction times are reduced from several minutes to a fraction of a second, as compared to state‐of‐the‐art (SOTA) viewpoint quality evaluation. Code and training data is available at https://github.com/schellmi42/viewpoint_learning , which is to our knowledge the biggest viewpoint quality dataset available. Michael Schelling, Pedro Hermosilla, Pere-Pau Vázquez, Timo Ropinski |
Comput. Graph. Forum | 3 |
| 2020 | Interactive framework for the visual exploration of colonic data
Jan Males, Eva Monclús, José Díaz 0003, Isabel Navazo, Pere-Pau Vázquez |
Comput. Graph. | 5 |
| 2019 | Visualization of Large Molecular TrajectoriesabstractThe analysis of protein-ligand interactions is a time-intensive task. Researchers have to analyze multiple physico-chemical properties of the protein at once and combine them to derive conclusions about the protein-ligand interplay. Typically, several charts are inspected, and 3D animations can be played side-by-side to obtain a deeper understanding of the data. With the advances in simulation techniques, larger and larger datasets are available, with up to hundreds of thousands of steps. Unfortunately, such large trajectories are very difficult to investigate with traditional approaches. Therefore, the need for special tools that facilitate inspection of these large trajectories becomes substantial. In this paper, we present a novel system for visual exploration of very large trajectories in an interactive and user-friendly way. Several visualization motifs are automatically derived from the data to give the user the information about interactions between protein and ligand. Our system offers specialized widgets to ease and accelerate data inspection and navigation to interesting parts of the simulation. The system is suitable also for simulations where multiple ligands are involved. We have tested the usefulness of our tool on a set of datasets obtained from protein engineers, and we describe the expert feedback. David Duran, Pedro Hermosilla, Timo Ropinski, Barbora Kozlíková, Àlvar Vinacua, Pere-Pau Vázquez |
IEEE Trans. Vis. Comput. Graph. | 6 |
| 2018 | Improving Perception Accuracy in Bar Charts with Internal Contrast and Framing EnhancementsabstractBar charts are among the most commonly used visualization graphs. Their main goal is to communicate quantities that can be visually compared. Since they are easy to produce and interpret, they are found in any situation where quantitative data needs to be conveyed (websites, newspapers, etc.). However, depending on the layout, the perceived values can vary substantially. For instance, previous research has shown that the positioning of bars (e.g. stacked vs separate) may influence the accuracy in bar ratio length estimation. Other works have studied the effects of embellishments on the perception of encoded quantities. However, to the best of the authors' knowledge, the effect of perceptual elements used to reinforce the quantity depicted within the bars, such as contrast and inner lines, has not been studied in depth. In this research we present a study that analyzes the effect of several internal contrast and framing enhancements with respect to the use of basic solid bars. Our results show that the addition of minimal visual elements that are easy to implement with current technology can help users to better recognize the amounts depicted by the bar charts. José Díaz 0003, Oscar Meruvia-Pastor, Pere-Pau Vázquez |
IV | 3 |
| 2018 | Progressive ray casting for volumetric models on mobile devices
Jesús Díaz-García, Pere Brunet, Isabel Navazo, Pere-Pau Vázquez |
Comput. Graph. | 4 |
| 2018 | A General Illumination Model for Molecular VisualizationabstractAbstract Several visual representations have been developed over the years to visualize molecular structures, and to enable a better understanding of their underlying chemical processes. Today, the most frequently used atom‐based representations are the Space‐filling, the Solvent Excluded Surface, the Balls‐and‐Sticks, and the Licorice models. While each of these representations has its individual benefits, when applied to large‐scale models spatial arrangements can be difficult to interpret when employing current visualization techniques. In the past it has been shown that global illumination techniques improve the perception of molecular visualizations; unfortunately existing approaches are tailored towards a single visual representation. We propose a general illumination model for molecular visualization that is valid for different representations. With our illumination model, it becomes possible, for the first time, to achieve consistent illumination among all atom‐based molecular representations. The proposed model can be further evaluated in real‐time, as it employs an analytical solution to simulate diffuse light interactions between objects. To be able to derive such a solution for the rather complicated and diverse visual representations, we propose the use of regression analysis together with adapted parameter sampling strategies as well as shape parametrization guided sampling, which are applied to the geometric building blocks of the targeted visual representations. We will discuss the proposed sampling strategies, the derived illumination model, and demonstrate its capabilities when visualizing several dynamic molecules. Pedro Hermosilla, Pere-Pau Vázquez, Àlvar Vinacua, Timo Ropinski |
Comput. Graph. Forum | 2 |
| 2018 | Visual Analysis of protein-ligand interactionsabstractAbstract The analysis of protein‐ligand interactions is complex because of the many factors at play. Most current methods for visual analysis provide this information in the form of simple 2D plots, which, besides being quite space hungry, often encode a low number of different properties. In this paper we present a system for compact 2D visualization of molecular simulations. It purposely omits most spatial information and presents physical information associated to single molecular components and their pairwise interactions through a set of 2D InfoVis tools with coordinated views, suitable interaction, and focus+context techniques to analyze large amounts of data. The system provides a wide range of motifs for elements such as protein secondary structures or hydrogen bond networks, and a set of tools for their interactive inspection, both for a single simulation and for comparing two different simulations. As a result, the analysis of protein‐ligand interactions of Molecular Simulation trajectories is greatly facilitated. Pere-Pau Vázquez, Pedro Hermosilla, Victor Guallar, Jorge Estrada, Àlvar Vinacua |
Comput. Graph. Forum | 1 |
| 2018 | Monte Carlo convolution for learning on non-uniformly sampled point cloudsabstractDeep learning systems extensively use convolution operations to process input data. Though convolution is clearly defined for structured data such as 2D images or 3D volumes, this is not true for other data types such as sparse point clouds. Previous techniques have developed approximations to convolutions for restricted conditions. Unfortunately, their applicability is limited and cannot be used for general point clouds. We propose an efficient and effective method to learn convolutions for non-uniformly sampled point clouds, as they are obtained with modern acquisition techniques. Learning is enabled by four key novelties: first, representing the convolution kernel itself as a multilayer perceptron; second, phrasing convolution as a Monte Carlo integration problem, third, using this notion to combine information from multiple samplings at different levels; and fourth using Poisson disk sampling as a scalable means of hierarchical point cloud learning. The key idea across all these contributions is to guarantee adequate consideration of the underlying non-uniform sample distribution function from a Monte Carlo perspective. To make the proposed concepts applicable to real-world tasks, we furthermore propose an efficient implementation which significantly reduces the GPU memory required during the training process. By employing our method in hierarchical network architectures we can outperform most of the state-of-the-art networks on established point cloud segmentation, classification and normal estimation benchmarks. Furthermore, in contrast to most existing approaches, we also demonstrate the robustness of our method with respect to sampling variations, even when training with uniformly sampled data only. To support the direct application of these concepts, we provide a ready-to-use TensorFlow implementation of these layers at https://github.com/viscom-ulm/MCCNN. Pedro Hermosilla, Tobias Ritschel 0001, Pere-Pau Vázquez, Àlvar Vinacua, Timo Ropinski |
ACM Trans. Graph. | 3 |
| 2017 | Mobile graphicsabstractcourse Share on Mobile graphics Authors: Marco Agus KAUST & CRS4 KAUST & CRS4View Profile , Enrico Gobbetti CRS4 CRS4View Profile , Fabio Marton CRS4 CRS4View Profile , Giovanni Pintore CRS4 CRS4View Profile , Pere-Pau Vázquez UPC UPCView Profile Authors Info & Claims SA '17: SIGGRAPH Asia 2017 CoursesNovember 2017 Article No.: 12Pages 1–259https://doi.org/10.1145/3134472.3134483Published:27 November 2017Publication History 1citation239DownloadsMetricsTotal Citations1Total Downloads239Last 12 Months19Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access Marco Agus, Enrico Gobbetti, Fabio Marton, Giovanni Pintore, Pere-Pau Vázquez |
SIGGRAPH ASIA (Courses) | 5 |
| 2017 | Physics-Based Visual Characterization of Molecular Interaction ForcesabstractMolecular simulations are used in many areas of biotechnology, such as drug design and enzyme engineering. Despite the development of automatic computational protocols, analysis of molecular interactions is still a major aspect where human comprehension and intuition are key to accelerate, analyze, and propose modifications to the molecule of interest. Most visualization algorithms help the users by providing an accurate depiction of the spatial arrangement: the atoms involved in inter-molecular contacts. There are few tools that provide visual information on the forces governing molecular docking. However, these tools, commonly restricted to close interaction between atoms, do not consider whole simulation paths, long-range distances and, importantly, do not provide visual cues for a quick and intuitive comprehension of the energy functions (modeling intermolecular interactions) involved. In this paper, we propose visualizations designed to enable the characterization of interaction forces by taking into account several relevant variables such as molecule-ligand distance and the energy function, which is essential to understand binding affinities. We put emphasis on mapping molecular docking paths obtained from Molecular Dynamics or Monte Carlo simulations, and provide time-dependent visualizations for different energy components and particle resolutions: atoms, groups or residues. The presented visualizations have the potential to support domain experts in a more efficient drug or enzyme design process. Pedro Hermosilla, Jorge Estrada, Victor Guallar, Timo Ropinski, Àlvar Vinacua, Pere-Pau Vázquez |
IEEE Trans. Vis. Comput. Graph. | 6 |
| 2017 | An experimental study on the effects of shading in 3D perception of volumetric models
José Díaz 0003, Timo Ropinski, Isabel Navazo, Enrico Gobbetti, Pere-Pau Vázquez |
Vis. Comput. | 5 |
| 2017 | Interactive GPU-based generation of solvent-excluded surfaces
Pedro Hermosilla, Michael Krone, Victor Guallar, Pere-Pau Vázquez, Àlvar Vinacua, Timo Ropinski |
Vis. Comput. | 4 |
| 2016 | Human-Document Interaction Systems - A New Frontier for Document Image AnalysisabstractAll indications show that paper documents will not cede in favour of their digital counterparts, but will instead be used increasingly in conjunction with digital information. An open challenge is how to seamlessly link the physical with the digital -- how to continue taking advantage of the important affordances of paper, without missing out on digital functionality. This paper presents the authors' experience with developing systems for Human-Document Interaction based on augmented document interfaces and examines new challenges and opportunities arising for the document image analysis field in this area. The system presented combines state of the art camera-based document image analysis techniques with a range of complementary technologies to offer fluid Human-Document Interaction. Both fixed and nomadic setups are discussed that have gone through user testing in real-life environments, and use cases are presented that span the spectrum from business to educational applications. Dimosthenis Karatzas, Vincent Poulain D'Andecy, Marçal Rusiñol, Antoni Chica, Pere-Pau Vázquez |
DAS | 5 |
| 2016 | High quality illustrative effects for molecular rendering
Pedro Hermosilla, Victor Guallar, Àlvar Vinacua, Pere-Pau Vázquez |
Comput. Graph. | 4 |
| 2016 | Real-Time Molecular Visualization Supporting Diffuse Interreflections and Ambient OcclusionabstractToday molecular simulations produce complex data sets capturing the interactions of molecules in detail. Due to the complexity of this time-varying data, advanced visualization techniques are required to support its visual analysis. Current molecular visualization techniques utilize ambient occlusion as a global illumination approximation to improve spatial comprehension. Besides these shadow-like effects, interreflections are also known to improve the spatial comprehension of complex geometric structures. Unfortunately, the inherent computational complexity of interreflections would forbid interactive exploration, which is mandatory in many scenarios dealing with static and time-varying data. In this paper, we introduce a novel analytic approach for capturing interreflections of molecular structures in real-time. By exploiting the knowledge of the underlying space filling representations, we are able to reduce the required parameters and can thus apply symbolic regression to obtain an analytic expression for interreflections. We show how to obtain the data required for the symbolic regression analysis, and how to exploit our analytic solution to enhance interactive molecular visualizations. Robin Skånberg, Pere-Pau Vázquez, Victor Guallar, Timo Ropinski |
IEEE Trans. Vis. Comput. Graph. | 2 |
| 2016 | Adaptive transfer functions - Improved multiresolution visualization of medical models
Jesús Díaz-García, Pere Brunet, Isabel Navazo, Frederic Pérez, Pere-Pau Vázquez |
Vis. Comput. | 5 |
| 2012 | Adaptive Cross-sections of Anatomical ModelsabstractAbstract Medical illustrations have been used for a long time for teaching and communicating information for diagnosis or surgery planning. Illustrative visualization systems create methods and tools that adapt traditional illustration techniques to enhance the result of renderings. Clipping the volume is a popular operation in volume rendering for inspecting the inner parts, though it may remove some information of the context that is worth preserving. In this paper we present a new editing technique based on the use of clipping planes, direct structure extrusion, and illustrative methods, which preserves the context by adapting the extruded region to the structures of interest of the volumetric model. We will show that users may interactively modify the clipping plane and edit the structures to highlight, in order to easily create the desired result. Our approach works with segmented volume models and non‐segmented ones. In the last case, a local segmentation is performed on‐the‐fly. We will demonstrate the efficiency and utility of our method. José Díaz 0003, Eva Monclús, Isabel Navazo, Pere-Pau Vázquez |
Comput. Graph. Forum | 4 |
| 2012 | Using Normalized Compression Distance for image similarity measurement: an experimental study
Pere-Pau Vázquez, Jordi Marco |
Vis. Comput. | 1 |
| 2010 | Real-time ambient occlusion and halos with Summed Area Tables
José Díaz 0003, Pere-Pau Vázquez, Isabel Navazo, Florent Duguet |
Comput. Graph. | 2 |
| 2009 | The virtual magic lantern: an interaction metaphor for enhanced medical data inspectionabstractIn Volume Rendering, it is difficult to simultaneously visualize interior and exterior structures. Several approaches have been developed to solve this problem, such as cut-away or exploded views. Nevertheless, in most cases, those algorithms usually require either a preprocess of the data, or an accurate determination of the region of interest, previous to data inspection. Eva Monclús, José Díaz 0003, Isabel Navazo, Pere-Pau Vázquez |
VRST | 4 |
| 2009 | Automatic view selection through depth-based view stability analysis
Pere-Pau Vázquez |
Vis. Comput. | 1 |
| 2007 | Omni-directional Relief ImpostorsabstractAbstract Relief impostors have been proposed as a compact and high‐quality representation for high‐frequency detail in 3D models. In this paper we propose an algorithm to represent a complex object through the combination of a reduced set of relief maps. These relief maps can be rendered with very few artifacts and no apparent deformation from any view direction. We present an efficient algorithm to optimize the set of viewing planes supporting the relief maps, and an image‐space metric to select a sufficient subset of relief maps for each view direction. Selected maps (typically three) are rendered based on the well‐known ray‐height‐field intersection algorithm implemented on the GPU. We discuss several strategies to merge overlapping relief maps while minimizing sampling artifacts and to reduce extra texture requirements. We show that our representation can maintain the geometry and the silhouette of a large class of complex shapes with no limit in the viewing direction. Since the rendering cost is output sensitive, our representation can be used to build a hierarchical model of a 3D scene. Carlos Andújar, Javier Boo, Pere Brunet, Marta Fairén González, Isabel Navazo, Pere-Pau Vázquez, Àlvar Vinacua |
Comput. Graph. Forum | 6 |
| 2007 | Automatic Light Source Placement for Maximum Visual Information RecoveryabstractAbstract The automatic selection of good viewing parameters is a very complex problem. In most cases, the notion of good strongly depends on the concrete application. Moreover, when an intuitive definition of good view is available, it is often difficult to establish a measure that brings it to the practice. Commonly, two kinds of viewing parameters must be set: camera parameters (position and orientation) and lighting parameters (number of light sources, its position and eventually the orientation of the spot). The first parameters will determine how much of the geometry can be captured and the latter will influence on how much of it is revealed (i.e., illuminated) to the user. Unfortunately, ensuring that certain parts of a scene are lit does not make sure that the details will be communicated to the user, as the amount of illumination might be too small or too high. In this paper we define a metric to calculate the amount of information relative to an object that is effectively communicated to the user given a fixed camera position. This measure is based on an information‐based concept, the Shannon entropy, and will be applied to the problem of automatic selection of light positions in order to adequately illuminate an object. In order to validate the results, we have carried out an experiment on users, this experiment helped us to explore other related measures. Pere-Pau Vázquez |
Comput. Graph. Forum | 1 |
| 2006 | Realtime automatic selection of good molecular views
Pere-Pau Vázquez, Miquel Feixas, Mateu Sbert, Antoni Llobet |
Comput. Graph. | 1 |
| 2004 | Virtual Museums: New added-value for Museums Web Sites
Joaquim Majó, Joaquim Martínez, Pere-Pau Vázquez |
ENTER | 3 |
| 2004 | Way-Finder: Guided Tours Through Complex Walkthrough ModelsabstractAbstract The exploration of complex walkthrough models is often a difficult task due to the presence of densely occluded regions which pose a serious challenge to online navigation. In this paper we address the problem of algorithmic generation of exploration paths for complex walkthrough models. We present a characterization of suitable properties for camera paths and we discuss an efficient algorithm for computing them with little or no user intervention. Our approach is based on identifying the free‐space structure of the scene (represented by a cell and portal graph) and an entropy‐based measure of the relevance of a view‐point. This metric is key for deciding which cells have to be visited and for computing critical way‐points inside each cell. Several results on different model categories are presented and discussed. Carlos Andújar, Pere-Pau Vázquez, Marta Fairén González |
Comput. Graph. Forum | 2 |
| 2004 | Bandwidth reduction for remote navigation systems through view prediction and progressive transmission
Pere-Pau Vázquez, Mateu Sbert |
Future Gener. Comput. Syst. | 1 |
| 2003 | Fast Adaptive Selection of Best Views
Pere-Pau Vázquez, Mateu Sbert |
ICCSA (3) | 1 |
| 2003 | Perception-Based Illumination Information Measurement and Light Source Placement
Pere-Pau Vázquez, Mateu Sbert |
ICCSA (3) | 1 |
| 2003 | Automatic View Selection Using Viewpoint Entropy and its Applications to Image-based ModellingabstractAbstract In the last decade a new family of methods, namely Image‐Based Rendering, has appeared. These techniques rely on the use of precomputed images to totally or partially substitute the geometric representation of the scene. This allows to obtain realistic renderings even with modest resources. The main problem is the amount of data needed, mainly due to the high redundancy and the high computational cost of capture. In this paper we present a new method to automatically determine the correct camera placement positions in order to obtain a minimal set of views for Image‐Based Rendering. The input is a 3D polyhedral model including textures and the output is a set of views that sample all visible polygons at an appropriate rate. The viewpoints should cover all visible polygons with an adequate quality, so that we sample the polygons at sufficient rate. This permits to avoid the excessive redundancy of the data existing in several other approaches. We also reduce the cost of the capturing process, as the number of actually computed reference views decreases. The localization of interesting viewpoints is performed with the aid of an information theory‐based measure, dubbed viewpoint entropy. This measure is used to determine the amount of information seen from a viewpoint. Next we develop a greedy algorithm to minimize the number of images needed to represent a scene. In contrast to other approaches, our system uses a special preprocess for textures to avoid artifacts appearing in partially occluded textured polygons. Therefore no visible detail of these images is lost. ACM CSS: I.3.7 Computer Graphics—Three‐Dimensional Graphics and Realism Pere-Pau Vázquez, Miquel Feixas, Mateu Sbert, Wolfgang Heidrich |
Comput. Graph. Forum | 1 |