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Lighting Data Exporter Utility 303
2–1312), the Physical Scale value is disregarded,
and you don’t need to change it.
•IfyouuseStandard lights (page 2–1288),the
Physical Scale value acts as a conversion scale
that the radiosity engine uses to calculate
energy. Set it to the equivalent of the brightest
light source in the scene. This will set the
appro priate conversion scale for reflections,
self-illumination, and all other non-physically
based elements a 3ds Max material offers.
However, if you use the Affect Indirect Only
flag in t he Logarithmic Exposure Control (page
3–297), you don’t need to worry about the
physical scale setting.
Spectrum bar—Sho ws the spectrum-to-intensity
mapping. The numbers below the spectrum range
from the Minimum to the Maximum settings.
When rendering with pseudo color, the spectrum
bar is displayed beneath the pseudo color image,
labeled either Luminance or Illuminance.
Lighting Data Exporter Utility
Utilities panel > U tilities rollout > Lighting Data Export
The Lighting Data Expor ter renders the active
viewport to images that include luminance (page
3–964) and illuminance ( page 3–955) data that can
be used for lighting analysis.
The Lighting Data Exporter does not render the
filesunlessyouhaveappliedanexposure control
(page 3–293) to the scene.
You can render to either the TIFF file (page
3–634) format. If you export to a TIFF file, the
utility renders a single image file that has sep arate
channels for luminance and illuminance (the file is
of the 32-bit SGI LogLUV image type).
Yo u c a n a l s o r e n d e r t o t h e PIC file (page 3–628)
format. If you export to a PIC file, the utility
renders two images: one containing luminance
data, and the other containing il luminance data
(see the descr iption of the File Name button,
below).
Interfa ce
File Name—Click the button to specif y a file name
for the rendering.
When you export to the PIC format, the Lighting
Data Exporter renders two fi les. It appends the
string “_Illuminance” to the name of one file, and
“_Luminance” to the other. For example, if you
type house asthefilename,theexporterrenders
to house_illuminance.pic and house_luminance.pic.
ImageSizegroup
Width—Sets the output width, in pixels.
Default=640.
Height—Sets the output height, in pixels.
Default=480.
Expor t—Click to render luminance and
illuminance data.
Wa rn in g : Unlike the renderer, if you click Export more
than once, this overwrites previously rendered files.