Agustín Trujillo

Forecasting and visualization of wildfires in a 3D geographical information system

This paper describes a wildfire forecasting application based on a 3D virtual environment and a fire simulation engine. A novel open-source framework is presented for the development of 3D graphics applications over large geographic areas, offering high performance 3D visualization and powerful interaction tools for the Geographic Information Systems (GIS) community. The application includes a remote module that allows simultaneous connections of several users for monitoring a real wildfire event. The system is able to make a realistic composition of what is really happening in the area of the wildfire with dynamic 3D objects and location of human and material resources in real time, providing a new perspective to analyze the wildfire information. The user is enabled to simulate and visualize the propagation of a fire on the terrain integrating at the same time spatial information on topography and vegetation types with weather and wind data. The application communicates with a remote web service that is in charge of the simulation task. The user may specify several parameters through a friendly interface before the application sends the information to the remote server responsible of carrying out the wildfire forecasting using the FARSITE simulation model. During the process, the server connects to different external resources to obtain up-to-date meteorological data. The client application implements a realistic 3D visualization of the fire evolution on the landscape. A Level Of Detail (LOD) strategy contributes to improve the performance of the visualization system.

An open source virtual globe framework for iOS, Android and WebGL compliant browser

The present article introduces the Glob3 Mobile, an efficient virtual globe framework, testable and freely accessible from the web and providing a real 3D navigation experience with smooth flying. We discuss the software design and the native code implementation for the family of iOS and Android mobile devices. In addition, a novel web experience is facilitated by supporting the globe through a WebGL compliant browser. Glob3 mobile enjoys a user friendly API that allows for testing and scripting new features on the globe. The paper discusses the software design, the technical rollout options and provides a comparison with other similar existing solutions.

An efficient terrain Level of Detail implementation for mobile devices and performance study

Abstract On the basis of traditional Terrain Quadtree algorithms this paper introduces a new Level Of Detail (LoD) criteria which allows the visualization of a virtual earth on many kinds of mobile devices with a suitable accuracy. The earth rendering system is intended to run beneath the threshold that resources of current devices impose, regarding especially the graphics hardware capabilities and the memory usage. At the same time, the system deals flawless with typical screen-based user interaction allowing smooth flying and rapid orientation changes of the camera. The present work analyses the memory and graphics requirements from a theoretical perspective. Finally, we give a useful performance study that compares the globe on some mobile and desktop devices, focusing on LoD techniques, visibility test, creation of texture tiles, uploading tiles to GPU, and rendering.

SmartPort: A Platform for Sensor Data Monitoring in a Seaport Based on FIWARE

Seaport monitoring and management is a significant research area, in which infrastructure automatically collects big data sets that lead the organization in its multiple activities. Thus, this problem is heavily related to the fields of data acquisition, transfer, storage, big data analysis and information visualization. Las Palmas de Gran Canaria port is a good example of how a seaport generates big data volumes through a network of sensors. They are placed on meteorological stations and maritime buoys, registering environmental parameters. Likewise, the Automatic Identification System (AIS) registers several dynamic parameters about the tracked vessels. However, such an amount of data is useless without a system that enables a meaningful visualization and helps make decisions. In this work, we present SmartPort, a platform that offers a distributed architecture for the collection of the port sensors’ data and a rich Internet application that allows the user to explore the geolocated data. The presented SmartPort tool is a representative, promising and inspiring approach to manage and develop a smart system. It covers a demanding need for big data analysis and visualization utilities for managing complex infrastructures, such as a seaport.

Multimodal Location Based Services—Semantic 3D City Data as Virtual and Augmented Reality

The visualization of cross-domain spatial data sets has become an important task within the analysis of energy models. The representation of these models is especially important in urban areas, in which the under-standing of patterns of energy production and demand is key for an efficient city planning. Location Based Services (LBS) provide a valuable addition towards the analysis and visualization of those data sets as the user can explore the output of different models and simulations in the real environment at the location of interest. Towards this aim, the present research explores mobile alternatives to the visual analysis of temporal data series and 3D building models. Based on the fields of numerical simulation, GIS and computer graphics, this work presents a novel mobile service that allows exploring urban models at different Level of Details (LoDs) using well-known standards such as CityGML. Ultimately, the project enables researchers, city planners and technicians to explore urban energy datasets in an interactive and immersive manner as Virtual Globes, Virtual Reality and Augmented Reality. Using models of the city of Karlsruhe, the final service has been implemented and tested on the iOS platform providing an empirical insight on the performance of the system. In addition, this research provides a holistic approach by developing one application that is capable of seamlessly change the visualization mode.

Glob3 Mobile: An Open Source Framework for Designing Virtual Globes on iOS and Android Mobile Devices

The widely development of mobile devices is contributing to a high demand in 3D graphics, as they have also become a very important requirement of modern applications. Virtual Globes integrating environmental data at any time or place, remain a challenge within the technical constraints imposed by mobile devices. We present Glob3 Mobile, an open source framework for the development of virtual globes on familiar iOS and Android mobile devices. The paper discusses the design and development choices for each platform. The aim of this work is twofold. First, to provide an efficient Virtual Globe application, testable and freely accessible from the web and providing a truly 3D navigation experience with smooth flying. Second, to provide the main software components to easily design and implement 3D Virtual Globes based applications, on both iOS and Android platforms.

Fast and accurate circle tracking using active contour models

In this paper, we deal with the problem of circle tracking across an image sequence. We propose an active contour model based on a new energy. The center and radius of the circle is optimized in each frame by looking for local minima of such energy. The energy estimation does not require edge extraction, it uses the image convolution with a Gaussian kernel and its gradient which is computed using a GPU–CUDA implementation. We propose a Newton–Raphson type algorithm to estimate a local minimum of the energy. The combination of an active contour model which does not require edge detection and a GPU–CUDA implementation provides a fast and accurate method for circle tracking. We present some experimental results on synthetic data, on real images, and on medical images in the context of aorta vessel segmentation in computed tomography (CT) images.

Tracking the Aortic Lumen Geometry by Optimizing the 3D Orientation of Its Cross-sections

We propose a fast incremental technique to compute the 3D geometry of the aortic lumen from a seed point located inside it. Our approach is based on the optimization of the 3D orientation of the cross-sections of the aorta. The method uses a robust ellipse estimation algorithm and an energy-based optimization technique to automatically track the centerline and the cross sections. In order to perform the optimization, we consider the size and the eccentricity of the ellipse which best fit the contour of the aorta on each cross-sectional plane. The method works directly on the original image and does not require a prior segmentation of the aortic lumen. We present some preliminary results which show the accuracy of the method and its ability to cope with challenging real CT (computed tomography) images of aortic lumens with significant angulations due to severe elongations.

Wildfire forecasting using an open source 3D multilayer geographical framework

This abstract describes the development of a wildfire forecasting plugin using Capaware. Capaware is designed as an easy to use open source framework to develop 3D graphics applications over large geographic areas offering high performance 3D visualization and powerful interaction tools for the Geographic Information Systems (GIS) community. Some other samples addressing this problem can be found in [Sherman et al. 2007] and [Thon et al. 2007].

Ellipse Motion Estimation Using Parametric Snakes

In this paper we propose a multiscale parametric snake model for ellipse motion estimation across a sequence of images. We use a robust ellipse parameterization based on the geometry of the intersection of a cylinder and a plane. The ellipse parameters are optimized in each frame by searching for local minima of the snake model energy including temporal coherence in the ellipse motion. One advantage of this method is that it just considers the convolution of the image with a Gaussian kernel and its gradient, and no edge detection is required. A detailed study about the numerical evaluation of the snake energy on ellipses is presented. We propose a Newton–Raphson-type algorithm to estimate a local minimum of the energy. We present some experimental results on synthetic data, real video sequences and 3D medical images.