Roberto Vivó

Learn More
Modeling and rendering of plants and trees requires generating and processing large numbers of polygons. Geometry simplification methods may be used to reduce the polygon count and obtain a multiresolution representation. However, those methods fail to preserve the visual structure of a tree. We propose a different approach: procedural multiresolution. We(More)
This paper presents a new method for realistic real-time rendering of tree foliage. Some approaches to this problem have been presented before but the quality of their results was not maintainable with respect to changes in view vector and observer distance. Our method is based on a hierarchy of images obtained from preprocessing the botanical tree(More)
We present a client/server system that is able to display 3D scenes on handheld devices. This kind of devices have important restrictions of memory and computing power. Therefore, we need to limit the amount of geometry sent by the server to each client. We extract the geometry that is visible for each client and send it. The clients render the geometry(More)
Space partitioning techniques are a useful means of organizing geometric models into data structures. Such data structures provide easy and efficient access to a wide range of computer graphics and visualization applications like real-time rendering of large data bases, collision detection, point classification, etc. Binary Space Partitioning (BSP) trees(More)
This paper presents a method to obtain a single continuos polygonal mesh representing a branched structure taken from a tree and modelled by a L-systems-based method. A refinement process is made once the model of the tree is obtained. This process produces smooth transitions in the tree areas joining the branches. That is, the overlapping problems and(More)
This paper presents a method to obtain a polygonal mesh representing the ramified structure of a tree. We use a method based on L-systems to model the tree. A refining process is applied once the model of the tree is obtained. Soft transitions are achieved in the areas of the tree where there are divisions. In this way, we avoid the possible superimposition(More)
Different methods can be used for learning, and they can be compared in several aspects, especially those related to learning outcomes. In this paper, we present a study in order to compare the learning effectiveness and satisfaction of children using an iPhone game for learning the water cycle vs. the traditional classroom lesson. The iPhone game includes(More)