2009

Target Rotation Spin group
Defines the angular velocity for each particle when it reaches the target
orientation.
Match Initial Spin Sets the angular velocity at the end of the transition period
to the same as the angular velocity when particle enters the event.
NOTE The axis of rotation might still be different, because it is calculated on the
fly to let the particle come to the target orientation.
Spin Rate Defines each particle's angular velocity, in degrees per second, when
it reaches the target orientation. Available only when Match Initial Spin is
off. Default=0.0.
For a smooth transition to the target orientation, set to 0.0.
Variation Defines a random variation in the Spin Rate value when a particle
reaches the target orientation. Default=0.0.
To obtain the final angular velocity for each particle, the system multiplies
the Variation value by a random number between -1.0 and 1.0, and then adds
the result to the Spin Rate value. For example, if Spin Rate=6.0 and
Variation=1.0, then the final angular velocity for each particle would be
between 5.0 and 7.0 degrees per second.
Ease In % Defines a curve in achieving the final spin rate. Default=0.0
When set to 0.0, the test produces a linear interpolation between the initial
and final spin rate, and when set to 100.0, the final spin rate is achieved earlier.
For the smoothest approach to the target orientation, set Spin Rate and
Variation to 0.0, and Ease In to 100.0.
Transition End group
Stop Spinning When on, halts particle rotation when it reaches the target
orientation. Default=on.
Even with Spin Rate spinner set to 0.0, we recommend that you keep this
check box on to avoid slow spinning at the end, due to computational
averaging and marginal errors.
Uniqueness group
The Uniqueness setting enables randomization of the Variation options.
Seed Specifies a randomization value.
New Calculates a new seed using a randomization formula.
2986 | Chapter 14 Space Warps and Particle Systems