Lighting and Graphics Effects for Real-Time Visualization of the Universe

Abstract: This work has been performed at SCISS AB, a company situated in Norrk öping and whose business lies in developing platforms for graphics visualization. SCISS's main software product, UniView, is a fully interactive system allowing the user to explore all parts of the observable universe, from rocks on the surface of a planet to galaxies and quasars in outer space. It is used mainly for astronomical and scientic presentation. The aim of this work has been to enhance the visual appearance of lighting eects in the solar system, which has included implementing atmospheric eects for planets, shadow casting and an enhanced representation of the sun. We have managed to implement a visually convincing atmosphere applicable to all of the planets in the solar system. The atmospheric eects can be viewed from space as well as from the surface of a planet and allow for a seamless transition between the two locations. The atmosphere simulates the eects of day and night, sunrise and sunset, and gives important depth cues through the eect of aerial perspective. Combining the atmospheric eects with an algorithm for rendering accurate soft shadows for spherical objects and a sun that varies in size with visibility has enabled the visualization of the phenomena of solar and lunar eclipses. This feature can be watched from space, where the shape of the shadow becomes apparent and can be studied, as well as from the planet's surface, where one can experience the darkening of the sky as the moon slowly obscures the sun and then observe the corona of the sun around the dark moon. All this can be run at interactive frame rates on ATI and Nvidia graphics cards using shader model 2.0 or above.