Real-Time Rendering of Planets with Atmospheres

This paper presents a real time technique for planetary rendering and atmospheric scattering effects. Our implementation is based on Nishita's atmospheric model which describes actual physical phenomena, taking into account air molecules and aerosols, and on a continuous level-of-detail planetary renderer. We obtain interactive frame rates by combining the CPU bound spherical terrain rendering with the GPU computation of the atmospheric scattering. In contrast to volume rendering approaches, the parametrization of the light attenuation integral we use makes it possible to pre-compute it completely. The GPU is used for determining the texture coordinates of the pre computed 3D texture, taking into account the actual spatial parameters. Our approach benefits from its independence of the rendered terrain geometry. Therefore, we demonstrate the utility of our approach showing planetary renderings of Earth and Mars.