Real-Time Rendering of Daylight Sky Scene for Virtual Environment

Realistic rendering of sky scene is important in virtual environment. Traditional methods are mostly based on skybox, thus failing to realistically simulate the change of sky scene under different weathers and conditions. In this paper, a new sky light model under different weathers for virtual environment is proposed. We first analyze the atmosphere characters of sky scene, and calculate the light path and light intensity into eyes through the atmosphere considering atmospheric scattering and refraction. Then for different weathers, by adapting a path tracing algorithm, the intensity distribution of sky light is gained. we also adopt the scattered volume model and GPU techniques to accelerate the calculation. Finally, various sky scenes in sunny day, foggy day, raining day and that with rainbow under different conditions are realistically rendered in real time.