Realistic sky rendering in real-time

This paper presents an effective method to render realistic sky in real-time. It is described below: Firstly, a sky light computation is achieved by using the analytic sky model, in which day and night changes are taken into account and light sources at night such as moonlight, starlight, zodiacal light and airglow are analyzed. Secondly, tone reproduction is employed to render realistic sky. The scotopic phenomenon is simulated to further get the night rendering realistic. Finally, the viewport-based sky geometry model and the rendering method for galaxy and stars are presented. The real-time rendering for the above algorithms was achieved by a graphics processing unit (GPU). The proposed method is suitable for rendering of outdoor scenery, which has been applied to a helicopter flight simulator successfully.