Sun Positioner and Physical Sky

A streamlined alternative to the Daylight System, the new Sun Positioner and Physical Sky provides a coordinated workflow for users of modern physically-based renderers.

• Command panel > Create panel > Lights panel > Object Type rollout > Sun Positioner

Similar to other available Sunlight and Daylight Systems, the Sun Positioner and Physical Sky uses light that follows the geographically correct angle and movement of the sun over the earth at a given location. You can choose location, date, time and compass orientation. You can also animate the date and time. This system is suitable for shadow studies of proposed and existing structures. In addition, you can animate Latitude, Longitude, North Direction, and Orbital Scale.

The primary advantage to the Sun Positioner and Physical Sky is the efficient and intuitive workflow compared to the legacy sunlight and daylight systems. The legacy systems consist of 5 separate plug-ins: the compass rose, the sun object, the sky object, the daylight controller, and the environment map. These are found in different locations in the interface; for example, the Daylight system is found in the Systems panel while its data location settings are found in the Motion panel.

This Sun Positioner and Physical Sky is found in a more intuitive location, the Lights panel. The Sun Positioner exists to position the sun in the scene. Date and location settings are found in the Sun Position rollout. Once the Sun Position object is created, the Environment map and Exposure Control plug-in are created with good default values. All parameters related to shading are only found in the Material Editor's Physical Sun & Sky rollout. This simplifies the workflow by avoiding duplication and also makes it less likely you will introduce inconsistencies.

The Sun Positioner and Physical Sky is renderer agnostic. It is up to the renderer to determine if it needs to internally support this feature using multiple light sources, like Mental Ray and Scanline, or as a simple Environment map, like ART or Iray. As is, it does implement the Scanline shading functions so it is fully functional with the Scanline renderer as an Environment map but not for illumination. Third party renderers can make use of this functionality to easily support the Sun/Sky shaders without actually having to implement the shaders.

Procedures

To use Sun Positioner and Physical Sky

1. On the Command panel, select Create and then Lights.
2. In the Object Type rollout, select Sun Positioner.
3. Choose a viewport in which to create a compass rose (the compass direction of your scene). This should be a Top or Perspective/Camera view.
4. Drag to create the radius of a compass rose (the radius is for display purposes only), and then release the mouse button and move the mouse to set the orbital scale of the sunlight over the compass rose.
5. Click to finish.
   You have two objects in your scene:

   • The compass rose, which is a helper object providing the world direction for your sun.
   • The sun itself, which is a child of the compass rose and is permanently targeted on the center of the compass rose.
6. In the Name and Color rollout, enter a name and select a display color.
7. In the Sun Position rollout, set the date, time, weather, and location settings.

   The default time is noon, and the default date and time zone are based on your computer's local settings. The default location is San Francisco, CA., USA.

   Generally, it's easiest to choose a location first, and then adjust the date and time.