8

Setting Units and Scale 581
Illumination settings by choosing Override Light
Object Sett ings.
There are three ways to convert standard light
intensities for Lightscape. Each method is useful
for different types of lighting. These are described
in the sections that follow.
Scenes Wh ere Ex act L ight Intens it ies A r e
Impor tant
These are scenes where you are u sing 3ds Max to
build a model, but you don’t require 3ds Max to
render the lighting well.
If exact intensities are important, using
photometric in your 3ds Max scene is the best
solution. But if your scene contains standard
lights, you can follow these steps:
1. Find the intensit y, in candelas, of the brightest
light y ou will place in your model.
2. As you create each light, set its Multiplier to
the r atio of the intensity of the light and the
intensity of the brightest light.
3. When you export the model, choose Maximum
Light Intensity Scale and set t he intensity value
to the intensity of the brig htest light. The lights
imported into Lightscape will have the exact
intensities you require.
Scenes W here You Want the L ights cape
Model to Appear as Close as Possible to
the R endered S cene
These are scenes where exact light intensities are
not important.
Follow this step:
• When you export the model, either choo se
Light Intensity At Distance and enter the
average distance between lights and the surfaces
they illuminate, or select Average Target
Distance if your lights are mostly targeted
spotlights. This will m atch the br i ghtness of
your lights at the selected distance, and will give
an overal l effect similar to 3ds Max.
S cenes wi t h Li ght s I mported f r om
Lightsca pe Solution (LS ) Files
In scenes with lights imported f rom Lightscape
Solution (*.
ls) files, as well as scenes that use
photometric lights, should already have physically
correct lighting. This method also works in scenes
where you have u sed standard lights with range
attenuation to simulate physical lights.
Note: If you import a Lightscape Solution (LS)
file but turn off Make Lightscape Lights, lights
are imported as s tandard lights. However, the
imported lights will have physically correct
attenuation settings.
Follow these steps:
1. For lights that do not use range attenuation,
use either of the methods described in the
preceding sections.
2. When y ou export the model, make sure Use
Attenuation is turned on. This will cause a
different intensity estimate to be used for lig hts
that use range attenuation.
S etti ng Units a nd S ca le
If your scene was not created at a realistic scale,
you need to specif y scaling that Lightscape will be
able to use.
Note: If your scene uses photometric lights, the
scaling should already be correct, so leave Scale
Factor set to 1, but be sure to choose the correct
units.
The controls for setting units and scale are on
the
General panel (page 3–592) of the Export
Lightscape Preparation File dialog.