Efficient Simulation of Light Scattering Effects in the Atmosphere

Abstract

Atmospheric light scattering encompasses intricate physical process, including diverse scattering mechanisms and optical parameters. Addressing the challenges posed by the computationally intensive task of deciphering this phenomenon, this study introduces an efficient real-time simulation strategy. The proposed approach employs a physics-driven atmospheric modeling, leveraging a unified phase function to emulate both Rayleigh and Mie scattering phenomena. The scattering integral is approximated and discretized using the concept of ray-marching to solve the scattering integral. Based on the characteristics of different light sources, accurate ray-marching lengths are determined, streamlining the computational trajectory of the light path. Additionally, the introduction of texture dithering enhances the randomness of the initial sampling positions. The Shadow Map algorithm is adeptly employed to generate shadow mapping textures, eliminating the need for light calculations within shadowed regions, thereby reducing the number of samples and computational workload. Finally, color synthesis is used to determine the rendering color of the atmosphere under various fog density conditions. Experimental results show that this approach significantly improves rendering efficiency, and achieves real-time rendering while maintaining a realistic light scattering effect compared with other advanced light scattering rendering methods.