9

Rotation Operator 153
Total—
Sets the number of emission p oints.
Available only when Distinct Points Only is on.
Default=10.
If Location Is Invalid group
Delete Par ticles—When on, if the software cannot
place a particle according to the current option, it
deletes the particle. When off, particle placement
is undefined; that is, it depends on other variables.
Default=off.
If the number of particles is more important than
thepositionontheobject,leavethisoff.However,
if exact placement is of higher priority than the
number of particles, turn Delete Particles on.
Uniqueness group
The Uniqueness setting enables randomization of
placement on the emitters.
Seed—Specifies a randomization value.
New—Calculates a new seed using a randomization
formula.
Attempts Ma x—When using the Separation option,
this specifies t he maximum number of times
Particle Flow will try to set particle positions that
maintain the requested distance. If unsuccessful
within this number of attemp ts, particles might be
closer together than the requested distance. Also
affects placement with Density By Material using
either of the Grayscale options.
Rotation Operator
Particle View (page 2–125) >ClickaRotationoperatorin
an event or add a Rotation operator to the particle system
and then select it.
The Rotation operator lets you set and animate
particle orientation during an event, with optional
random variation. You can apply orientation in
any of five different matrices: two random and
three explicit. For some options you can set a
degree of random variation or divergence from the
specified orientation.
To c a u s e p a r t i cles to s p i n , u s e t he Spin oper a tor
(page 2–154).
Interfa ce
The user interface appears in the parameters panel,
on the right side of the Particle View dialog.
Orientation Matrix group
The Orientation Matrix setting includes opt ions
that give particles random orientations, or let you
specify orientation in any of three different ways.
Default=Random 3D.
Random 3D—Gives each particle an arbitrary,
random 3D orientation.
Random Horizontal—Gives each particle an
arbitrary, random 3D orien tation about the Z axis
only. Rotation about the X and Y axes doesn’t
change (unless Divergence is used), so the particles
remain vertical.
World S pa ce —Orientation is specified in the world
coordinate space.
Use the X/Y/Z settings to specif y the orientation
for all particles.