8

Spawn Test 227
Inter face
The user interface appears in the parameters panel,
ontherightsideoftheParticleViewdialog.
In the context of Spawn, a
parent is the origin al
particle from which new particles are spawned.
Spawn R ate A nd Amount group
Use these settings to specify how often p art icles
aretospawn,themeasurementsystemtouse,
andothervaluesrelatedtohowmanyparticles
are spawned.
Once—Particles spawn one time only. For each
existing particle, one new one is born.
Delete Parent—When on, deletes each orig inal
particle from which a new one is spawned.
Available only w ith the Once option.
Per S econd—Lets you specify a number of particles
to spawn every second. For example, if you use the
default Rate setting of 10.0, at 30 fps a new p article
is born e very t hree f rames.
Rate—The number of particles to spawn per
second. Available only with the Per Second option.
By Travel Distance—Lets you spawn new particles
at regular intervals over the path of a moving
parent part icle.
Step Size—Thesystemspawnsanewparticleevery
time the parent moves this distance, in system
units.
Spawnable—The percentage of p articles in the
current event that will spawn new particles. This is
determined once for each particle, when it enters
the event. However, the parameter is animatable.
Default=100.0.
For values other than 100.0, Spawnable uses a
randomized selection process, which is affected
by the Uniqueness Seed value. For example,
w ith five parent particles, Offspring # =1, and
Spawnable=80.0, you might get any number of
spawned particles between two and five. T he
average per spawning would be four, howev er.
Offspring #—The number of new particles the
system creates from each p arent par ticle for each
spawning event. Default=1.
Variation—TheamountbywhichtheOffspring#
value can vary randomly. Default=0.0.
To obtain the actual test value for each particle, the
system multiplies the Variation value by a random
number between -1.0 and 1.0, and then applies the
result as a percentage of the Offspring # setting.