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How 3ds Max Objects Are Converted to Lightscape 589
Conver tin g Standard Lights
For standard lig hts, there are three methods for
converting the lights when exporting them to
Lightscape: scaling intensity, matching intensity,
and using attenuation.
•
Scaling Intensity—Takes a valu e you e nte r
and multiplies that times the standard lig ht’s
Multiplier value. The result becomes the
intensity of the converted light in candelas.
•
Matching Intensit y—Calculates the brightness
of a light by matching the apparent intensity
of the standard light and Lightscape light at a
set distance you can choose. This can give you
agoodestimateofthegeneralbrightnessof
a3dsMaxscene. Thedefaultdistanceis2.5
meters (about 8 feet), which is a goo d estimate
for typical interior models. If you are using
targeted spotlights, you can also use the average
distance between the lights and their ta rgets.
Note: The two previous metho d s a re mutually
exclusive, and you must choose one method
or the other.
•
Attenuati on—Estimates the brightness of the
light based on the range attenuation for lig hts
that use range attenuation. This method simply
matches the light intensity at the distance 25
percent of the way from the inner range to
the outer range. If you use this option, all
lights with range attenuation wi ll be converted
using this metho d , and all other lights will
be converted using either the scale or match
intensity methods. This metho d also properly
inverts the brightness of lights imported from
Lightscape solutions.
There are two methods for converting spotlight
angles. When the Preserve Spotlight Angles option
is
not on, the beam ang le for a converted spotlight
issettotheanglewherethestandardspotlight
illuminates at one-half intensity, which matches
the illumination of a Lightscape spotlight at the
beam angle. When the Preserve Spotlight Angles
option
is on, the beam ang le is set to the standard
light’s hotspot angle.
IfyouwantLightscapetoilluminateascene
thesameas3dsMax,youshouldn’tturnon
Preserve Spotlight Angles, because the converted
spotlights will have significantly different intensity
distributions. Turn on Preserve Spotlight Angles
when you want to use 3ds Max to specify the
spotlight angles that Lightscape will use.
Sincehiddenlightsin3dsMaxcanilluminatea
scene, they are exported unless they aren’t turned
on.
Converting Materials
Lightscape does n’t have the same materials found
in 3ds Max, and only a few material parameters
are exported. The following material components
are exported:
•Diffusecolor
•Shininess
• Shininess st rength
• Diffu se map, if one is assigned
If you use a mu lti/sub-object material to assign
different materials to faces in an object, the
exporter assigns the proper material to each
face. If you use a material that isn’t a standard
material, the exporter performs a depth-first
search of the material hierarchy until it finds a
standard material, which is exported. If the object
doesn’t have a materia l, or the exporter can’t find a
material, it creates a standard material that using
the object’s wireframe color, and exports that
material.