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1334 Chapter 15: Lights and Cameras
Shadows group
On—Determines whether the current light casts
shadows or not. Default=on.
Sha dow M e tho d dr op-down l i st —Determines
whether the renderer uses shadow maps (page
3–1010), ray-traced shadows (page 3–1000),
advanced ray-traced shadows (page 3–1000),or
area shadows (page 3–911), to generate shadows
for this light.
The “mental ray Shadow Map” type is provided
for use with the mental ray renderer (page 3–78).
When you choose this shadow type and enable
shadow maps (on the Shadows & Displacement
rollout (page 3–114) of the Render Scene dialog),
shadows use the mental ray shadow-map
algorithm. If this type is chosen but you render
w ith the default scanline renderer, no shadows
appear in the rendering.
Note: When shadow maps are enabled and the
shadow map type is Shadow Map, the mental ray
renderer attempts to translate the shadow map
settings into comparable settings for mental ray
shadow maps. (The results might not be what
you expected.) In all other cases, the mental r ay
renderer generates ray-traced shadows.
Each shadow type has its par t icular controls:
•
Advanced r ay-tr aced shadows—See Advanced
Ray-Traced Parameters Rollout (page 2–1356)
and Optimizations Rollout (page 2–1361).
•
Area shadows—See Area Shadows Rollout
(page 2–1357) and Optimizations Rollout (page
2–1361).
•
mental ray shadow maps—See mental ray
Shadow Map Rollout (page 2–1360).
•
Ray-traced shadows—See Ray-Traced Shadow
Parameters Rollout (page 2–1363).
•
Shadow maps—See Shadow Map Parameters
Rollout (page 2–1363).
Tip: Use ray-traced or advanced ray-traced shadows
when you want shadows cast by opacity-mapped
objects. Shadow-mapped shadows don’t recognize
the transparent portions of the mapping, and as a
result they don’t look con vincing.
Use Global Settings—Tur n on to use global s ett ings
for shadows cast by this light. Turn off to enable
individual control of the shadows. If you choose
not to use the global settings, you must choose
which method the renderer will use to generate
shadows for this particular light.
When Use Global Settings is on, the shadow
parameters switch over to show you what the
global settings are. This data is shared by every
other light of this class. When U se Global Settings
is off, the shadow parameters are specific to that
part icular light.
Exclude button
Excludes selected objects from the effects
of the light. Click this button to display the
Exclude/Include dialog (page 2–1335) .
Excluded objects still appear lit in shaded
viewports. Exclusion takes effect only when you
render the scene.
Roll Angle Man ipulator
To change the roll angle of a target ligh t, you
can use a manipulator. This can be usef ul if the
lightdoesnotcastaroundbeam,orifitisa
projector light (see Advanced Effects Rollout (page
2–1341)). To display the manipulator, select the
light, r i ght-click it, and then click Roll Angle
Manipulator Toggle in the Tools 1 (upper left)
quadrant of the quad menu.