9

Sunlight and Daylight Systems 419
diameter of the hotspot is set to 65 per cent of the
longest diagonal length of the scene extents (page
3–1007).
Pr ocedur es
To create a Sunlight or Day light sy stem:
1.
On the Create p anel, click Systems
and then click Sunlight or Daylight.
Alternatively, you can create a Daylight system
fromtheCreatemenu>LightsorSystems
submenu.
2. Choose a viewport in which to create a compass
rose (the compass direction of your "world").
This should be a Top or Perspective/Camera
view.
3. 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 sun light over the
compass rose. This can be any distance you
find convenient, since directional and IES Sun
lights produce parallel il lumination regardless
of where their icon is located. Click to finish.
Upon creation you have two objects in your
scene:
•Thecompass rose (page 2–27),whichis
ahelperobjectthatprovidestheworld
direction for your sun.
• The light itself, wh ich is a child of the
compass rose, and is permanently targeted
on the center of the compass rose.
If you created a Daylight system, the Daylight
Parameters rollout on the Modify panel lets
you choose the type of sunlight and skylight.
The Sunlight drop-down list lets you choose
IESSun,mrSun,orStandard(directional).
The Sky light drop-down list lets you choose
IES Sky, mr Sky, or Skylight. These lists
also offer you the options of choosing no
sunlight or no sky light.
Controls for the geographic location and time
of day are on the Motion panel. The default
timeisnoon,andthedefaultdateandtimezone
are based on your computer’s loc a l settings.
The default location is San Francisco, CA.
The directional light created by the system is
managed by two special controllers: Solar Dat e
and S olar Time. After you create your system,
you can access its creation par ameters (t ime
and date, locat ion, orbital scale, and location)
in the Motion panel for the directional light.
The parameters are interrelated, so you can
adjust them in any order. G eneral ly, it’s easiest
to choose a location first, and then adjust the
date and time. You can access the par ameters
for selected sunlight or skylight objects in the
Modify panel. The radius of the compass rose
is also editable f rom the Modify panel, after
selecting the compass rose object.
If Date/Time position is selected the Sun
and Sky multipliers are automatically set and
animated according to their position. They can
be edited only by using the Manual Position
override.
Tip: UseExposureControlwithDaylightifyour
scene rendering is too br i ght or too dark.
Ex ample: To create a sha dow study :
1.
Create a Da ylight system.
2. OntheModifypanel,setthedateandLocation.
Note: Once the Daylight system has been
created, you can find these controls on t he
Motion panel.
3. Turn on the A uto Key button.
4. In the Con trol Parameters Time group, adjust
the Hours spinner to a start time in early
morning.