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mental ray Sun & Sky 1313
Inter face
On—Turns the sky light on and off in the viewport.
Multiplier—Adjusts the intensity of the skylight.
When this is set to 1.0, the intensity will be
physically accurate based on angle. You can,
however, override this by changing the value.
This is usef ul for doing night shots with artificial
lighting.
Sk y Color—The color swatch opens the Color
Selector (page 1–161), which lets you set the color
of the sky.
Coverage group
Cle ar, Pa rtly Clo u d y, Clou d y—This choice
determinestheextenttowhichlightisscattered
through the sky. Use t he sl ider to set the control to
one of the named settings or anywhere in between.
Render group
Note: Thesecontrolsareunavailablewhenthe
mental ray renderer is active.
Cast Shadows—Causes the sky light to cast
shadows.
A great deal of processing is dedicated to the
calculation of the subtle shadows cast by skylight
(page 3–1012).Ifshadowsarenotimportant
in your model, you can disable them and save
substant ial amounts of processing time. However,
the results will not be as realistic.
Note: The Cast Shadows toggle has no effect when
using radiosity or the light tracer.
Note: IES Sky objects w ill not cast shadows in an
ActiveShade rendering (page 3–17).
Rays per Sample—The number of rays used to
calculate skylight falling on a given point in the
scene. For animation you should set this to a high
value to eliminate flickering. A va lue of around 30
should eliminate flickering.
Increasing the number of rays increases the quality of your
image. However, it also increases rendering time.
Ray Bias—The closest distance at which objects
can cast shadows on a given point in the scene.
Settingthisvalueto0cancausethepointtocast
shadows upon itself, and se tting it to a large value
canpreventobjectsclosetoapointfromcasting
shadows on the point.
menta l r ay S un & S ky
Daylight system > Modify panel > Daylight Parameters
rollout > Sunlight/Skylight drop-down lists > mr Sun/mr
Sky
ThementalraySun&Skysolutionisdesignedto
enable physically plausible daylight simulations
and accurate renderings of daylight scenarios. In
3dsMax,thisisachievedthroughtheuseoftwo