One special light is available to simulate the effect of sunlight and sky illumination (natural lighting).
The settings for the sun and sky light are located on the Autodesk Rendering window, Environments tab. The settings are saved per file.
The rays of the simulated sunlight are parallel and have the same intensity at any distance. The angle of the light from the sun is controlled by the geographic location you specify for your model, and by the date and time of day.
Additional sky illumination adds extra light to the scene, simulating the effect of light scattered by the atmosphere throughout the scene. Whereas the rays of the sun are parallel and of a yellowish hue, the light cast from the atmosphere comes from all directions and is distinctly bluish in color. The sky effects are visible in the Scene View for both realistic and photorealistic visual styles.
To add the sun and sky light to your model, follow this workflow: