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178 Chapter 11: Space Warps and Particle Systems
Multi-Shape R andom Order—
When on, assig ns
shapestoparticlesinrandomorder.Whenoff,
Particle Flow emits each shape in the multi-shape
object as a single par ticle, in the order of the
shape’s X coordinate. In other words, the shape
w ith the lowest X -ax is coordinate i s emitted first,
then the one with the next highest, and so on. The
optionisavailableonlyifatleastoneofSeparate
Particles For group check boxes is on. Default=off.
For example, if you want the particles to spell out
awordorphrase,useextrudedtextcreatedinthe
Front viewport as the reference object, turn on
Separate Particles For > Group Elements, but leave
Multi-Shape Random Order off.
Animated Shape—When on, particles use any
animationinthereferenceobject,includingcyclic
animation applied with the Parameter Cur ve
Out-of-Range Types con trols. When off, the
particles are not animated.
With this option, you can use the Animation Offset
K eying controls to specify how to synchronize the
reference-object animation with the particles. See
the next section.
Note: Aparticlethatusesthisoptionisanimated
only while in the event containing the Shape
Instance operator. If it moves to another event that
doesn’t contain a shape operator, it keeps the same
shape, but the animation stops. The easiest way to
keep the animation going from event to event is
to place the Shape Instance operator in the
global
event (page 3–1043)
. Otherwise, you need to place
theoperatorineacheventinwhichtheparticle
should be animated.
Acquire Current S hape—When on, Particle Flow
acquirestheparticleshapefromthereference
object as each particle ent ers the event. Thus, if the
reference object is animated, particles that enter at
different times get different shapes. However, these
shapes are not animated. When the option is off,
the shape is acquired from frame 0. Default=off.
This option is available only when Animated
Shape is off.
Animation Offset Keying group
These controls are available only when Animated
Shape is on.
Sync B y—Lets you choose how to synchronize
reference-object animation with the particles.
•
Absolute T ime—All particles have the same
shape at any given moment.
•
Par ticle Age—Animation of the reference object
is synchronized with particle age: Frame 0 of
the reference-object animation corresponds to
the frame of each particle’s birth.
•
Event Dur ation—Frame 0 of the reference-object
animation corresponds to the moment the
part icle enters the event.
Rand Offset—When on, randomly varies the star t
of each particle’s animation. Use the numeric
setting to specify the number of fr a me s by which
the animation start can vary.
Update Par ticle Shape—Refreshes instanced
particle shapes from the reference object . Use this
after changing an object in a hierarchical ref erence
object.
In most cases, Part icle Flow automatically updates
instanced particles when changes are made to the
reference object. However , in some cases, when
youchangeanobjectdeepinahierarchy,the
particle instances might not be updated. In such
a case, click Update Particle Shape to refresh the
instances.
Uniqueness group
The Uniqueness setting enables changing the
randomization of the scale variation, animation
offset, and the multi-shape random order.
Seed—Specifies a randomization value.