Conference Presentations by I. Remolar
The development of augmented reality systems that combine virtual elements with the real world is... more The development of augmented reality systems that combine virtual elements with the real world is currently
increasing. This paper presents an augmented reality system that renders the virtual elements from models
based on the light fields. The use of these models allow us to obtain higher level of photorealism than representations
that render polygons. Using light fields also allows us to keep constant the rendering time. The
presented system has been implemented using the Open Source library ARToolKit and a spherical model of
the light field based on the direction-and-point parameterization (DPP) with some associated depth information.
The system has been validated using different light fields, and it has been compared its performance with
a classic version of the ARToolKit library based on VRML files. The presented augmented reality system can
be applied to the visual inspection of synthetic objects of great complexity or based on real images.
Papers by I. Remolar
There are many tools nowadays for videogame development. Generally, this kind of tools have been ... more There are many tools nowadays for videogame development. Generally, this kind of tools have been created for users with programming skills. This restriction, although is useful to programmers, excludes other professionals like graphics artists or designers. For this reason we propose an intuitive and simple environment that let professionals to design videogames without any programming knowledge. Our design allows to develop complex games visually without writing a single line of code, allowing to create game objects (actors) with complex interaction. The work uses a visual approach with diagrams for the specification of rules which are be defined without need of programming. 1. Game creation environment The new game creation environment we propose has a different approach compared to traditional ones. There are several game development environments in the market, however our software has been built in order to avoid any programming at all. This approach allows users without any pro...
Lecture Notes in Computer Science, 2000
Multiresolution modelling of polygonal surface meshes has been presented as a solution for the in... more Multiresolution modelling of polygonal surface meshes has been presented as a solution for the interactive visualisation of scenes formed by hundreds of thousands of polygons. On the other hand, it has been shown that representing surfaces using sets of triangle strips or fans greatly reduces visualisation time and provides an important memory savings. In this paper we present a new method to model polygonal surface meshes. Like the previously explained Multiresolution Ordered Meshes (MOM), this method permits the efficient management of an ample range of approximations of the given model. Furthermore, this method utilises the triangle fan as its basic representation primitive. Experiments realised with data sets of varying complexity demonstrate reduced storage space requirements, while retaining the advantages of MOMs.
Proceedings of the …, 2002
The application of virtual worlds through Internet for teaching allows that the student can subme... more The application of virtual worlds through Internet for teaching allows that the student can submerge himself in friendly environments that make learning more pleasant. This article presents three educational applications developed in these worlds. The first, for vocabulary learning, shows a set of virtual worlds designed in VRML where the student interacts with different objects. When an object is selected, its written name can be read and the student can listen to its pronunciation. In the following application, a virtual classroom, the created world can be shared simultaneously by several users. There are diverse materials available as in the traditional classrooms, for example a blackboard, laser pointer and a slide projector. Finally, the latest advances in the creation of virtual environments have been applied in the third application using a game engine. This has made possible the design of a more realistic world where the student can interact with other users and share his experiences.
Multimedia Tools and Applications, 2013
Online virtual trade fairs are becoming a popular way of establishing economic trade relationship... more Online virtual trade fairs are becoming a popular way of establishing economic trade relationships nowadays. In the current context of the world economy, new ways of creating virtual environments where suppliers can show their products to potential customers are increasingly in demand. Some people can be found in this kind of scenario representing a role such as, for example, the administrator, the customers or the suppliers. The interaction between them is one of the most important characteristics of these commercial environments. Taking all these concepts into account, this article presents a 3D virtual trade fair that has been defined using an agent-oriented approach. This approach makes it possible to model, understand and implement the virtual economic environment, where interaction is the norm. Moreover, it makes it easy to add new components and meet new requirements in order to develop an open architecture that continuously changes and evolves. In this virtual trade fair, the chosen methodology has been Gaia, widely used for agent-oriented analysis and design of multi-agent systems.
Computers & Graphics, 2011
The main problem in the real-time rendering of vegetation is the massive amount of primitives to ... more The main problem in the real-time rendering of vegetation is the massive amount of primitives to be rendered. These primitives are needed to fully describe the geometry of the plants. However, some of them are not visible depending on the location of the viewer. This work focuses on this fact to interactively reduce the amount of geometry needed to represent
Computers & Graphics, 2002
Recent technological advances have favored the apparition of highly detailed objects and, consequ... more Recent technological advances have favored the apparition of highly detailed objects and, consequently, their availability for a wide diversity of applications. Normally, these objects are represented by means of complex polygonal surfaces formed by hundreds of thousands of polygons, which produce important increases in the costs of storage, transmission and visualization. Multiresolution modeling, which allows an object to be represented by means of a set of approximations, each with a different number of polygons, has been successfully presented as a solution for the efficient manipulation of this type of objects. Although the first references to multiresolution modeling appeared more than 20 years ago, most of the multiresolution schemes specifically applied to polygonal surfaces have been proposed recently. This paper, after a brief review of multiresolution modeling, presents a characterization of the most interesting multiresolution schemes for arbitrary polygonal surfaces. The objective is to make the similarities and differences between them easily visible. With this aim, a series of characteristics is enumerated. These characteristics have commonly been used to define the multiresolution schemes and they are arranged together depending on whether they refer to the applications, to the input data or to the internal operation.
lsm.dei.uc.pt
Resumen—La aplicación de los mundos virtuales para la docencia a través de Internet hacen que el ... more Resumen—La aplicación de los mundos virtuales para la docencia a través de Internet hacen que el alumno pueda sumergirse en ambientes amigables que hacen más ameno el aprendizaje. Este artículo presenta tres aplicaciones docentes desarrolladas en estos ...
Outdoor scenes require vegetation to make them look realistic. Current hardware cannot afford rea... more Outdoor scenes require vegetation to make them look realistic. Current hardware cannot afford real-time rendering of these scenes because of the large number of polygons. Multiresolution modelling has been successfully presented as a solution to the problem of efficient manipulation of highly detailed polygonal surfaces. This article describes a new continuous multiresolution hardware-oriented model that can represent tree foliage with different levels of detail. The multiresolution model presented in this paper, Level of Detail Foliage, takes advantage of the programmable rendering pipelines nowadays available in most video cards. The geometry of the foliage is divided into a number of clusters, in some of which the detail can change while the rest of the clusters remain unaltered. This division of the foliage remarkably diminishes the number of vertices sent to the graphics system because only the information of the changed clusters are updated. The independent clusters condition ...
One of the most important challenges in real-time rendering of outdoor scenes is the representati... more One of the most important challenges in real-time rendering of outdoor scenes is the representation of vegetation. This is due to the vast amount of polygons that are used to model vegetable species. The present automatic simplification algorithms produce acceptable results in the trunks and the branches, but not in the foliage of a tree. After simplification with the existing methods, the trees seem to be less leafy. In this paper, a new automatic simplification algorithm for this part of the tree is presented, the Foliage Simplification Algorithm. It diminishes the number of polygons in the crown, while maintaining the appearance. It uses a new method, leaf collapse: two leaves disappear to create a new one. The leaves obtained after collapsing preserve an area similar to that of the collapsed leaves 1.
Triangle strips are widely used as a method to accelerate the visualisation process of polygon mo... more Triangle strips are widely used as a method to accelerate the visualisation process of polygon models in interactive graphics applications. Another widely used method to improve drawing speed is the utilisation of multiresolution models. These models are constructed based on simplification algorithms.
Abstract. Interactive rendering of outdoor scenes is currently one of the most important challeng... more Abstract. Interactive rendering of outdoor scenes is currently one of the most important challenges in computer graphics. This article presents a new method of real-time visualization of trees and plants that combines both multiresolution modeling techniques and the dynamic generation of impostors. In our method, trees and plants are represented by continuous view-dependent levels of detail. This enables us to represent many complex tree models with variable resolution. The number of primitives rendered per tree is reduced according to their importance in the scene without loss of leafiness. Furthermore, trees are visualized using dynamic impostors that take advantage of the frame-to-frame coherence inherent in tree-dimensional scenes. The impostors avoid the need to redraw all the geometry of the scene continuously. This method permits visualization of outdoor scenes with a high number of trees in interactive applications such as computer games or virtual reality, adapting the leve...
Variable resolution level-of-detail is an important application of multiresolution modeling, sinc... more Variable resolution level-of-detail is an important application of multiresolution modeling, since te use of dierent resolutions across the surface allows interactive visualization of highly detailed objects. Multiresolution Ordered Meshes (MOM) was rst introduced as a model that achieves the ecient management of an ample range of uniform resolution levels-of-detail and presents reduced storage space requirements. In this paper, we introduce an algorithm capable of retrieving variable resolution levels-of-detail from a multiresolution MOM representation without having to reorganize data in new structures or store new information. The proposed algorithm starts from the level of highest detail and simplies it adaptively to reach the required resolution in each area of the surface. Experiments with data sets of varying complexity demonstrate that the new algorithm obtains variable resolution levels of detail while retaining the advantages of MOM. Keywords: multiresolution modeling, lev...
Most of the previous multiresolution models use exclusively the triangle graphic primitive both i... more Most of the previous multiresolution models use exclusively the triangle graphic primitive both in the data structure and in the rendering stage. Only a few models use another graphic primitive in this rendering process and just one uses the triangle fan as the basic primitive of the model. In this paper we present the first multiresolution model, Multiresolution Triangle Strips, that uses the triangle strip in the data structure and in the rendering stage. Each triangle strip is represented as a graph and all levels-of-detail of this strip are stored in it. The extraction algorithm traverses the graph to obtain the triangle strip at the demanded resolution. The use of this primitive speeds up the rendering process as the number of vertices sent to the graphic system is reduced.
Real-time rendering of vegetation is one of the most important challenges in outdoor scenes. This... more Real-time rendering of vegetation is one of the most important challenges in outdoor scenes. This is due to the vast amount of polygons that are used to model vegetable species. Multiresolution modeling has been successfully presented as a solution to the problem of efficient manipulation of highly detailed polygonal surfaces. In order to construct a multiresolution model, a simplification method must be used. The previously introduced Foliage Simplification Algorithm, FSA, obtains different approximations of a tree model. This automatic simplification method diminishes the number of polygons that form the crown while maintaining its leafy appearance. In this paper a multiresolution model for trees based on this simplification algorithm is presented. Its distinctive property is that the unit of information managed by this scheme is the leaf, four vertices determining two triangles. This characteristic allows us an efficient manipulation of the results obtained by FSA. Our multiresol...
El realismo siempre ha sido uno de los factores requeridos en las escenas de ambientes arquitectó... more El realismo siempre ha sido uno de los factores requeridos en las escenas de ambientes arquitectónicos generadas por ordenador. Los profesionales dedicados a arquitectura e interiorismo han acudido con asiduidad al renderizado para mostrar sus proyectos. No obstante, los avances en la tecnología de motores de juegos hace posible hoy en día que estos ambientes se muestren en tres dimensiones y en tiempo real, permitiendo a los usuarios interaccionar con los ambientes creados.
Triangles meshes are the most popular standard model used to represent polygonal surfaces in Comp... more Triangles meshes are the most popular standard model used to represent polygonal surfaces in Computer Graphics. Drawing these meshes as a set of independent triangles involves sending a vast amount of information to the graphic engine. The use of primitives such as triangle fans and strips, which make use of the connectivity information between the triangles in the mesh, dramatically reduces the amount of information sent to the graphic engine. The Multiresolution Triangle Strips scheme takes advantage of this characteristic in order to represent a multiresolution model as a set of multiresolution triangle strips. A multiresolution triangle strip is made up of the original strips and all of its Levels of Detail. Each of these multiresolution strips is represented as a graph that is traversed to recover the demanded LOD. A Multiresolution Triangle Strip model uses the triangle strip primitive both in the data structure and in the rendering stage. The Multiresolution Triangle Strip is...
Behaviour & Information Technology
Analysing observer preferences when presenting a product in a rendered scene: 2D vs. autostereosc... more Analysing observer preferences when presenting a product in a rendered scene: 2D vs. autostereoscopic 3D displays This research compares the way the image of a product included within a rendered scene shown on an autostereoscopic 3D display is rated versus the same image shown in a 2D display. The purpose is to understand the observer's preferences and to determine the features that a composition should have to highlight the product and to make its presentation more attractive to observers, thereby helping designers and advertisers who use both displays to prepare images to make them more effective when visually presenting a product. The results show that observers like the images on autostereoscopic 3D displays slightly more than those presented by means of 2D displays. On both displays the product is perceived more quickly when it is larger than the other elements and is shown with greater chromatic contrast, but a composition is seen as more attractive when the chromatic relationship between all the elements is more harmonious.
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Conference Presentations by I. Remolar
increasing. This paper presents an augmented reality system that renders the virtual elements from models
based on the light fields. The use of these models allow us to obtain higher level of photorealism than representations
that render polygons. Using light fields also allows us to keep constant the rendering time. The
presented system has been implemented using the Open Source library ARToolKit and a spherical model of
the light field based on the direction-and-point parameterization (DPP) with some associated depth information.
The system has been validated using different light fields, and it has been compared its performance with
a classic version of the ARToolKit library based on VRML files. The presented augmented reality system can
be applied to the visual inspection of synthetic objects of great complexity or based on real images.
Papers by I. Remolar
increasing. This paper presents an augmented reality system that renders the virtual elements from models
based on the light fields. The use of these models allow us to obtain higher level of photorealism than representations
that render polygons. Using light fields also allows us to keep constant the rendering time. The
presented system has been implemented using the Open Source library ARToolKit and a spherical model of
the light field based on the direction-and-point parameterization (DPP) with some associated depth information.
The system has been validated using different light fields, and it has been compared its performance with
a classic version of the ARToolKit library based on VRML files. The presented augmented reality system can
be applied to the visual inspection of synthetic objects of great complexity or based on real images.