9

1310 Chapter 15: Lights and Cameras
for Illuminating Engineering Society ; see IES
Standard File Format (page 2–1328).)
Outdoor scene illuminated by the IES Sun light
The mental ray renderer g ives physically accurate
results for IES Sun, and renderings that use it will
appear similar to renderings done with the default
scanline renderer. You do not need to turn on
Final Gather for light from IES Sun to render.
Note: Whileyoucancreatedaylightlights
manually, you should use them in conjunction
w ith the Daylight system to get the best results.
The Daylight system combines the two daylight
componentsofsunandskyinaunifiedinterface.
Tip: If you use the IES sun or sky with the
Logarithmic Exposure Control (page 3–297),turn
on both the Daylight and Exterior options. This
will pro vide greater control for properly mapping
the higher energy levels to RGB colors. In addition,
it is important to set the Physical Scale to the
brightest light source in your scene. If the IES Sun
is used, set the Physical Scale to 90000 cd.
Note: When you add an IES Sun light, 3ds Max
automatically assigns a Look At controller (page
2–344) to it, with the light’s target object assigned
as the Look At target. You can use the controller
settings on the Motion panel to assign any other
object in the scene as the Look At target.
Interfa ce
On—Turnssunlightonandoffintheviewport.
Targeted—Applicable only when you add the IES
Sun lig ht d i rect ly, rather t han as p art of a Daylight
system (page 1–418). When on, the light is targeted
and you can change the target distance by moving
thetarget.Thedistancebetweenthelightandits
target is displayed to the right of the check box.
When off, you can set this value directly.
Cast Shadows—Sets whether the sunlight casts
shadows or not.
Intensity—The intensity of the sun light. The color
swatch to the right of the spinner opens the Color
Selector (page 1–161) to set the color of the light.
Typical intensities in a clear sky are around 90,000
lux.
Note: Intensity is set automatically and cannot be
set manually if the sun is under the control of a
daylight system.
Shadows g roup
On—Determines whether the sunlight casts
shadows or not.
Sha dow M ethod drop-down list —Determines
whether the renderer uses shadow maps (page