ABSTRACT

Early attempts at atmospheric scattering can be found in [Klassen 87] and [Nishita et al. 93]. Recent implementations with an emphasis on real time are [Hoffmann and Preetham 02], [O’Neil 05], and [Bruneton and Neyret 08]. A common theme of all these approaches is finding ways to efficiently evaluate or precompute the Chapman function, Ch(x, χ). This is the density integral for a ray in a spherically symmetric, exponentially decreasing atmosphere.