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World Space Orientation is specified in the world coordinate space.
Use the X/Y/Z settings to specify the orientation for all particles.
Speed Space The coordinate space for particle orientation is determined by
the particles' direction upon entering the event.
By default, using the Speed operator on page 2871 > Along Icon Arrow option,
particles are aimed straight down when born.
Use the X/Y/Z settings to specify the orientation for all particles.
Speed Space Follow The coordinate space for particle orientation is determined
continually while the particles are in the event. Thus, by default, particles
constantly reorient themselves to “aim” in the direction they're traveling.
For example, if you add a
Find Target test on page 2970 to the end of the default
Event 01, move the target sideways, and set Rotation to Speed Space Follow,
the particles start out pointing straight down, as oriented by the Speed
operator, and then gradually reorient themselves to point in the direction
they're traveling: toward the target.
Use the X/Y/Z settings to specify the orientation for all particles. The
Divergence setting is unavailable when using Speed Space Follow.
X/Y/Z Set the basic orientation about the particles' local axes. Unavailable
with the Random 3D and Random Horizontal options.
Divergence Defines the range of variation (in degrees) for particle orientation.
The actual deviation is calculated at random within this range. Unavailable
with the Random 3D or Speed Space Follow option. Default=0.0.
Restrict Diverg[ence] To Axis When on, lets you use the Divergence Axis
controls to set the axis to which divergence will be applied. When off, the
software uses a random axis for each particle. Unavailable with the Random
3D or Speed Space Follow option. Default=off.
Divergence Axis Use the X/Y/Z settings to set the axis to which divergence
will be applied. Default=1,0,0. Range=-1.0 to 1.0.
To specify one of the world axes, set the corresponding parameter to any
non-zero value, and the others to 0. A negative value flips the axis. The numeric
values come into play when you want to use an axis that's not aligned with
the X, Y, or Z axis. In that case, you specify multiple non-zero values whose
effect is relative to one another. For example, if you want the axis to be
oriented halfway between the positive X and Y axes, you would set X and Y
to the same positive amount. The actual value doesn't matter. Similarly, to
set the axis to 30 degrees (1/3 of the angle) from the X axis to the Y axis, you'd
set the Y value to twice that of the X value. For example, X=0.2 and Y=0.4, or
X=0.5 and Y=1.0.
2862 | Chapter 14 Space Warps and Particle Systems