Lumberyard
User Guide (Version 1.15)

Setting Daytime Atmospheric Effects

To create dynamic daytime sky atmospheric effects, you modify sun and light-scattering setting that affect the appearance of distant objects, which shift in color due to atmospheric interference. These settings do not directly affect the rendering of objects or environment lighting colors and intensities.

To set daytime atmospheric effects

  1. In Lumberyard Editor, choose Tools, Other, Time Of Day.

  2. In the Time of Day Tasks pane, under Tasks, choose Toggle Advanced Properties to view all parameters.

  3. In the Parameters pane, under Sky Light, adjust the following parameters as needed:

    Sun intensity

    Sets the illuminance of the sun and uses an RGB sun color value to compute the atmosphere color. You can use this parameter in conjunction with Sun color to provide desired scene luminance. For bright sunlight, you can use an average illuminance value of 120000 lux. The intensity of the sun decreases as it nears the horizon, so you can add keys to the timeline to lower the intensity value appropriately. To accurately render shadows at night time, you can add keys to the timeline and set the value to 5.

    Sun intensity multiplier

    Sets the brightness of the sun. The brightness is multiplied by the sun intensity to yield the overall color.You can use this parameter in conjunction with Sun color multiplier to provide desired scene luminance. Higher values result in brighter skies. Lower values simulate an eclipse.

    Mie scattering

    Controls mie scattering, which is caused by pollen, dust, smoke, water droplets, and other particles in the lower portion of the atmosphere. Mie scattering occurs when the particles that cause the scattering are larger than the wavelengths of radiation that are in contact with them. Mie scattering is responsible for the white appearance of clouds.

    Higher values create a hazy sky. Lower values create a clear sky. For a balanced sky, you can set this value to 4.8.

    Rayleigh scattering

    Controls rayleigh scattering, which is sunlight scattering from atmospheric gases. Rayleigh scattering occurs when the particles that cause the scattering are smaller than the wavelengths of radiation that are in contact with them. As the wavelength decreases, the amount of scattering increases. Rayleigh scattering is responsible for the blue appearance of the sky.

    Higher values create a red-yellow sky. Lower values create a blue sky. For a blue daytime sky and red-yellow sunset sky, you can use the default value of 2.0.

    Sun anisotropy factor

    Controls the sun's apparent size. As this value approaches -1.0, the sun's disk becomes sharper and smaller. Higher values create a larger, fuzzier disk. For a balanced size, you can set this value to -0.995.

    Wavelength R, G, B

    Sets the hue (RGB values) of the atmosphere. You can create different atmospheres by adjusting the color values and gradients. This can be particularly useful with rayleigh scattering, when you choose a sun intensity of pure, bright white.