A Visualization Framework for Large-scale virtual astronomy

Motivated by advances in modern positional astronomy, this research attempt to digitally model the entire Universe through computer graphics technology. Our first challenge is space itself. The gigantic size of the Universe makes it impossible to put everything into a typical graphics system at its own scale. The graphics rendering process can easily fail because of limited computational precision. The second challenge is that the enormous amount of data could slow down the graphics; we need clever techniques to speed up the rendering. Third, since the Universe is dominated by empty space, objects are widely separated; this makes navigation difficult. We attempt to tackle these problems through various techniques designed to extend and optimize the conventional graphics framework, including the following: power homogeneous coordinates for large-scale spatial representations, generalized large-scale spatial transformations, and rendering acceleration via environment caching and object disappearance criteria. Moreover, we implemented an assortment of techniques for modeling and rendering a variety of astronomical bodies, ranging from the Earth up to faraway galaxies, and attempted to visualize cosmological time; a method we call the Lightcone representation was introduced to visualize the whole space-time of the Universe at a single glance. In addition, several navigation models were developed to handle the large-scale navigation problem. Our final results include a collection of visualization tools, two educational animations appropriate for planetarium audiences, and state-of-the-art-advancing rendering techniques that can be transferred to practice in digital planetarium systems