Interactive visual analysis has been a key component of gaining insights in information visualization area. However, the amount of data has increased exponentially in the past few years. Existing information visualization techniques lack scalability to deal with big data, such as graphs with millions of nodes, or millions of multidimensional data records. Recently, the remarkable development of Graphics Processing Unit (GPU) makes GPU useful for general-purpose computation. Researchers have proposed GPU based solutions for visualizing big data in graphics and scientific visualization areas. However, GPU based big data solutions in information visualization area are not well investigated. In this thesis, I concentrate on the visualization of big data in information visualization area. More specifically, I focus on visual exploration of large graphs and multidimensional datasets based on the GPU technology. My work demonstrates that GPU based methods are useful for sensemaking of big data in information visualization area. / Master of Science

Interactive applications with 3D graphics are used everyday in a lot of different fields, such as games, teaching, learning environments and virtual reality. The scenarios showed in interactive applications usually tend to present detailed worlds and characters, being the most realistic as possible. Detailed 3D models require a lot of geometric complexity. But not always the available graphics hardware can handle and manage all this geometry maintaining a realistic frame rate. Simplification methods attempt to solve this problem, by generating simplified versions of the original 3D models. These simplified models present less geometry than the original ones. This simplification has to be done with a reasonable criterion in order to maintain as possible the appearance of the original models. But the geometry is not the only important factor in 3D models. They are also composed of additional attributes that are important for the final aspect of the models for the viewer. In the literature we can find a lot of work presented about simplification. However, there are still several points without an efficient solution. Therefore, this thesis focuses on simplification techniques for 3D models usually used in interactive applications.