2009

Rate To specify the number of particles emitted per second, choose Rate, and

then set the value. The operator emits this number of particles per second

starting at the Emit Start frame and ending at the Emit Stop frame.

If you specify a birth rate value that isn’t an integer multiple of the system

frames-per-second value (set in the Time Configuration dialog), Particle Flow

uses interpolation to determine when to emit particles. For example, if you

use the system default rate of 30 frames per second, and set the birth rate to

4, the system would emit each particle at intervals of seven or eight frames if

Subframe Sampling is off, or at intervals of 7.5 frames if Subframe Sampling

is on.

Total The calculated total number of particles emitted by the operator.

Subframe Sampling Turning this on helps avoid particle "puffing" by emitting

particles at a much higher subframe resolution (that is, throughout each

frame), rather than using the relatively coarse frame resolution. Default=on.

"Puffing" is the effect of emitting separate "puffs" or clusters of particles, rather

than a continuous stream. This effect is especially noticeable when the emitter

is animated.

Turn off Subframe Sampling to cause particles to be emitted exactly at frame

times. This makes it easier to sort particles by their age later.

TIP If, when using the Collision on page 2960 or Collision Spawn test on page 2964,

you experience an irregular particle stream, try turning off Subframe Sampling.

Birth Script Operator

Particle View on page 2811 > Click Birth Script in an event or add a Birth Script

operator to the particle system and then select it.

The Birth Script operator enables creation of particles within the Particle Flow

system using a MAXScript script. The script can use any program functionality

available to MAXScript.

The default script (3dsmax\scripts\particleflow\example-scriptbirth.ms) emits

particles for 100 frames in a wavy, circular path. To see this, turn off or delete

any Speed and Position operators in the event.