9

Avoid Behavior 1213
designated as targets, click the Multiple Selection
button.
Multiple Selection—Opens the Select dialog to let
you designate multiple targets. When you have
more than one target, you can set delegates to
move toward the closest ta rget in the group, or to a
computed average of the target positions.
Look Ah ead—The number of frames in advance
of the current frame that the software looks for
potential collisions. Default=30.
Har d R a dius—Distance from the target’s pivot
point, in multiples of the delegat e’s bounding
sphere, where no penetration should occur.
Default=1.0.
Tip: Because the hard radius’ center is the pivot
point, Avoid may not work as expected with target
objectswhosepivotpointisnotcentered,such
as the box primitive. For best results, use the
Hierarchy panel > Adjust Pivot rollout controls to
centerthepivottotheobject.
Display Hard R adius—Enables display of a
wireframespherethatdepictstheextentofthe
Hard Radius setting. D efault=off.
Steer To Avoid group
Steer To Avoid is used by delegates to steer precisely
around anticipated future collisions based on the
delegates’ cur rent speed and direction. Delegates
using this approach can pass very close to one
another.
Detour Angle—Maximum necessary turning angle
relative to the direction of delegate’s goal that
delegate will steer to avoid rather than slow down
and wait. Default=360. Range=0-360.
Tip: To disable turning for avoidance, thus a llowing
only braking, set Detour Angle to 0. This forces
delegates to remain directed toward their goal so
that they must slow down and wait until there is a
clearing in front of them, much like an audience
queuing to leave through a n exit after a concert.
Brake Pressure—Determineshowstronglya
delegatewillreactwhenitencountersanavoided
object. Higher values make the delegate more
likely to slow down or stop. Lower values will cause
delegates to look for a way around the obstacle so
they can keep going, sometimes causing delegates
to veer off in unexpected directions. Default=2.0.
Repel group
Repel is a general separation force that is based
only on the spatial position. D elegates use this to
keep from getting into situations where they might
side-swipe each other or where they might get so
close that Steer To Avoid is too difficult to achieve.
Strength—Determines the strength of the repelling
force; higher values result in greater repulsion
force. Default=0.2. Range=0.0 to 1.0.
Radius—Maximum distance from delegate’s
bounding sphere within which "repel" avoidance
is sensed and carried out. Default=3.0.
Fa lloff—Therateatwhichthestrengthdiminishes
between the Repel radius and the hard radius. A
value of 1.0 indicates a linear falloff. Higher values
causethestrengthtofallofftozeromorerapidly
withdistance,thusfocusingitseffectcloserto
thedelegate’shardradius. Lowervaluesreduce
the r ate of diminishment, with a Falloff setting
of 0.0 ind ic ating that the strength is the same at
theRadiusdistanceasitisattheHardRadius.
Default=3.0.
Display R epel R a dius—Enables display of a
wireframespherethatdepictstheextentofthe
Repel setting. Default=off.
Vector Field group
If you’ve applied a Ve c tor Field s p a ce w ar p ( p age
2–1241) to an object in your scene, you can
specify t he vector field as an object to avoid. The
distinction is this: When used w ith the Space Warp
behavior (page 2–1221), delegates use the vector