8

mental ray Shadow Map Rollout 1205
Increasing jitter blends the individual shadow samples.
Area Li ght Dimensions group
Thesearethedimensionsappliedtoavirtuallight
that is used to compute the area shadow ing. They
donotaffecttheactuallightobject.
Lengt h—Sets the length of the area shadow.
Width—Sets the width of the area shadow.
Height—Sets the height of the area shadow.
mental ray S hadow Ma p R ollout
Create panel > Lights > Create a light. > General
Parameters rollout > Select “mental ray Shadow Map
shadows.” > mental ray Shadow Map rollo ut
Choosing “mental ray Shadow Map” as the
shadow type tells the
mental ray renderer (page
3–77)
to generate shadows using the mental ray
shadow-map algorithm. If you render with the
default scan line renderer (page 3–37) instead, no
shadows appear in the rendering.
Interfa ce
Map S ize—Sets the resolution of the shadow map.
Thesizeofthemapisthesquareofthisvalue.
Greaterresolutionsrequiremoretimetoprocess,
but produce more accurate shadows. Default=512.
Sample R ange—When greater than zero, generates
soft-edged shadows. This value specifies the area
of the map to soften, by removing portions of the
map as specified by Samples. Defau lt=0.0.
IfyousetSampleRangetobegreaterthanzero,
youmustalsosetSamplestobegreaterthanzero,
toobtainasoftshadoweffect.
Directional lights require Sample Range to have a
greater value than spotlights require.
Samples—Sets the number of samples to remove
from a shadow map when generating soft shadows.
Default=1.
Use B ias—When on, changes the map bias
(page 3–1060)
.Increasingthevaluemovesthe
shadow farther away from the shadow casting
object. Default=10.
Transparent Shadows group
Enable—When on, shadow maps are saved with
multiple Z-layers, and can have transparency.
Default=off.
Co lor—When on, surface color affects the color of
the shadow. Default=on.