9

Position Objec t Operator 149
Use the Position Object settings to control the
initial placement of particles on the emitter. You
can set the emitter to emit p articles f rom its
surface, volume, edges, vertices, or pivot, or from a
sub-object selection. You c an a lso control particle
emission with a material applied to the object.
Alternatively, you can use the Position Icon operator
(page 2–147) to emit particles from the Particle
Flow icon.
Note: Typically, you would use Position Object in a
birth event, so the particles appear initially at the
emitter object(s). If you use it in a non-birth event,
theparticlesjumptothedesignatedemitter(s)
upon entering the event. This could be useful for a
teleportation effect.
Tip: The default speed operator, Speed (page
2–159),typicallyusestheParticleFlowiconto
control the direction of the particle flow, so if the
emitter object(s) and the icon aren’t coincident
and alig ned, you might get unexpected results.
For better control over the direction of par ticle
movement w hen using Position O bject, use the
Speed By Surface operator (page 2–167) instead and
designateasSurfaceGeometrythesameobject(s)
as with Position Object.
Procedure
To use Position Object:
1.
Create a Particle Flow system and one or more
mesh objects to use as emitters. Animate
the emitter objects and set particle system
parameters as necessary.
2. In Particle View, add a Position Object operator
to the birth event, replacing the Position Icon
operator if one exists. Click the operator to
display its parameters.
3. In the Emitter Objects group, click Add, and
then select an object to serve as the emitter.
Alternatively, click By List and then use the
Select Emitter Objects dialog to designate one
ormoreobjectsasemitters.
4. Use the Location drop-down list to choose
where the particles should appear on the
emitter: surface, ver t ices, and so forth.
5. Set other options as necessary. For example, if
you want the par ticles to u se the same motion
as the emitter at the time of emission, turn on
Inherit Emitter Movement. Or if you’re using
an emitter object whose shape is animated, turn
on Animated Shape.