Creating a CIE Standard Overcast Sky Ambient Source

This sky model is based on the publication of the spatial distribution of daylight - CIE standard overcast and clear sky ISO 15469:2004(E)/CIE S 011/E:2003 .

To create a CIE Standard Overcast Sky Source:

  1. From the Light Simulation tab, click Ambient and click Overcast .
  2. If you want to modify the Zenith direction, in the 3D view, select a line (normal to the ground).
  3. Set the Luminance of the entire sky in cd/m2.
    Tip: The value usually ranges from a 1000 to 20000 cd/m².
    Note: The value must be strictly higher than 0 cd/m².
  4. From the Spectrum drop-down list:
    • Select Blackbody to set the temperature of the source spectrum in Kelvins.
    • Select Library and click Browse to load a .spectrum file.
  5. If you want to see the file's properties or edit the file, click Open file to open the Spectrum Editor .
  6. In Optional or advanced settings , adjust the size of the rays displayed in the 3D view.
The Ambient Source appears in the Simulation panel. In the 3D view, the four cardinal points are displayed.