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170 Chapter 11: Space Warps and Particle Systems
or negative values to move them closer together.
Default=100.0
Accel(eration) Limit—When on, lets you set a
maximumaccelerationvaluethatcanbeapplied
to particles’ motion. When off, the software uses
any necessary acceleration. D efault=on, 1000.0.
Tip: UsealowerAccelLimitvalueforsmooth
motion, and a highe r value when greater accuracy
is needed, such as when the particles should hit
a small target. You can a nimate this settin g (use
Sync By > Event Duration) to specify different
appropriate values, depending on the required
results.
Speed L imit —When on, lets you set a maximum
speed value that can be applied to p art icles’
motion. When off, the software uses any necessary
speed. Default=off, 600.0.
Range group
You can set a volu me and falloff within which the
force takes effect, either as absolute distances or
relative to particle size. Default=Absolute Size.
Absolute Size—Choose this to set the core r adius
and falloff zone as absolute distances, in system
units.
Co re Radius—The distance from each particle’s
pivot point, in system units, within which the force
is applied at full strength. Default=10.0
Fa lloff Zone—Thedistancebeyondthecoreradius,
in system units, over which the force diminishes
from full strength to 0. Default=10.0
Relative to Par ticle Size—Choose this to set the core
radius and fa lloff zone as percentages, relative to
theradiusofeachparticle.Theparticleradiusis
determined by measur ing the distance from the
pivotpointtothefarthestcornerofitsbounding
box.
Co re %—The distance from each particle, as a
percentage of the par t icle radius, w ithin which the
force is applied at full strength. Default=200.0
Fa lloff %—Thedistancebeyondthecoreradius,as
a percentage of the radius, over which the f orce
diminishes f rom f ul l strength to 0. Default=100.0
Variation % —The amount by which range values
can vary randomly, as a percentage of the specified
values. The software uses the same random
variation value for both Core and Falloff values,
whetherabsoluteorrelative.Default=0.0
Forexample,ifyouchooseAbsoluteSize,set
Core Radius to 40 and Falloff Zone to 20, and set
Variation % to 50, then each particle’s actual core
radius will be a random number in the range 20 to
60, and the falloff zone a random number in the
range 10 to 30. For each particle, the software uses
the same Variation % va lue, so if Core Radius is
determined to be 20, then Falloff Zone would be
10.
Scope group
By default, the Keep Apart force keeps particles
only in the current event (that is, the event that
contains the K eep A part operator) apart from each
other when used locally, or particles in each event
in the current
flow (page 3–1036) apart when
used global ly. These sett ings let you alternatively
keep particles away from particles in other events
or flows without affecting the behavior of latter.
Default=Current Event.
Current Event—Keeps particles in the current event
only away from each other.
When used globally, keeps par ticles in each event
in the current flow apart from each other, but not
apart from particles in other events in the flow.
Cu rren t Particle System—Keeps particles in the
current event away from each other, and away
from all other particles in the current
flow (page