Real-time rendering of sky scene considering scattering and refraction

Realistic rendering of sky scene is important in game development and virtual reality. Traditional methods did not consider both the affect of atmospheric scattering and refraction, thus failing to realistically simulate the change of shape, color, and light ring of sky scene. In this paper, a new sky light model considering atmospheric scattering and refraction is proposed. We first calculate the refractional track of light through the atmosphere according to the refraction index. Then we adopt the scattered volume model to simplify the calculation of scattering light intensity. By adapting a path tracing algorithm considering refraction, the intensity distribution of sky light is calculated. Finally, various sky scenes in sunny day, foggy day, and that with rainbow and mirage under different conditions are realistically rendered in real time.