Constant Dome

Courtesy of Frame

Sky type in Constant Dome mode + sun.

The Constant Dome sky model allows you to create a consistent color or gradient dome for lighting your scene.

The parameters to control the Constant Dome are:

  • Intensity (cd/m2): Type in the intensity of the Sky Dome in cd/m2. It is a common way to specify how much light is emitted.
  • Zenith: Specify the color of the dome at the zenith (the highest point above our head)
  • Horizon: Specify the color of the dome at the horizon.
  • Mid Point (degrees): Specify the transition between the Zenith and Horizon colors. This value indicates the angle at which the contribution of the colors is equal, where 0º and 90º correspond to Horizon and Zenith respectively. If you want a consistent color for your dome, simply choose the same color for both Zenith and Horizon slots. You can drag and drop colors from one color slot to the other, to copy the same exact color.

The Constant Dome can also include the sun contribution, adjusted in the same way as it is adjusted on the Physical Sky model.

  • Sun: Switch direct sunlight on/ off. For an overcast sky, you simply have to disable the direct contribution of the sun. 
  • Sun Power: A multiplier that controls the amount of light emitted from the sun. Higher values than the default 1 will make the sun emit more light, lower values will emit less. A value of 2 means the sun in your scene emits twice as much light as the Earth’s sun.
  • Sun Temperature: Temperature of the sun’s spectral radiation. The default value of 5777ºK is the most common value measured outside the Earth’s atmosphere. Lowering this value will give the sky and scene illumination a yellow tint, higher values will give the illumination a blue tint. Although it is possible to change this value for different looks, it is better to leave it at default and instead change the other atmosphere parameters for accurate and predictable results.
Location and Time (Latitude and Longitude mode)

You can specify the orientation of the sun by setting the position on earth and the time of day and month.

  • City: List of cities to quickly choose a location. The list is a text file which you can edit to add or delete locations. It can be found in your Maxwell installation folder (cities.txt).
  • Latitude/Longitude: Earth positions to calculate the sky/ sun light direction.
  • Date/Now: Allows you to set the date. Clicking the “Now” button sets the time and date to your computer’s current time and date.
  • Time/GMT: Set the time and the GMT offset.
  • Ground Rotation: Allows you to rotate the north direction. This is useful when you want to reposition the sunlight without changing the location or date/ time settings which would change the sky illumination.
  • Google Earth™ Data: Allows you to import a KMZ/ KML file to set the location.
Location and Time (Angles mode)

You can specify the orientation of the sun by using spherical angles.

  • Zenith: Vertical angle. Similar concept on sky positioning as latitude on Earth positioning.
  • Azimuth: Horizontal angle. The angle between the projected vector and a reference vector on the reference plane. Similar concept on sky positioning as longitude on Earth positioning. 
Location and Time (Direction)

You can specify the orientation of the sun by specifying a vector.

  • X: The X coordinate of the sun direction vector.
  • Y: The Y coordinate of the sun direction vector.
  • Z: The Z coordinate of the sun direction vector.