8

Avoid B eh avior 1065
Multiple S election—
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 t a rget in the group, or to a
computed average of the target positions.
Look Ahea d—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 delegate’s bounding
sphere, where no penet ration should occur.
Default=1.0.
Tip: B ecause 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. Default=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 A ngle—Maximum necessary turning angle
relative to the direction of delegate’s goal that
delegate will steer to avoid r ather t han slow down
and wait. Default=360. Range=0-360.
Tip: To disable turning for avoidance, thus allowing
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 an 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. Delegates use t his 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—Determ ines the strength of the repelling
force; hig her 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 c arried out. Default=3.0.
Fa lloff—Therateatwhichthestrengthdiminishes
between the Repel radius and the hard radius. A
value of 1.0 indic ates a linear falloff. Higher values
causethestrengthtofallofftozeromorerapidly
withdistance,thusfocusingitseffectcloserto
thedelegate’shardradius. Lowervaluesreduce
the rate of d iminishment, with a Falloff setting
of 0.0 indicating that the st rength is the same at
theRadiusdistanceasitisattheHardRadius.
Default=3.0.
Display Repel Ra dius—Enables display of a
wireframespherethatdepictstheextentofthe
Repel setting. Default=off.
Vector Field group
If you ’ve applied a
Ve c to r F i e l d s p a c e w a r p to an
object in your scene, you can specify the vector
field as an object to avoid. The distinction is
this: When used with the
Space Warp behav ior
(page 2–1073)
, delegates use the vector field to