2009

Phase Sets the initial particle rotation, in degrees. This has no meaning for
fragments, which always begin with zero rotation.
Variation The percent of variation of the Phase.
Spin Axis Controls group
These options determine the spin axis for the particles, and provide a partial
method of applying motion blur to the particles.
Random The spin axis for each of the particles is random.
Direction of Travel/Mblur (Not available with the Blizzard particle system.)
Rotates the particles about a vector formed by the direction in which they're
moving. This option also lets you apply a form of motion blur to the particles
by using the Stretch spinner. For further information, see
Achieving Particle
Motion Blur
on page 3010.
Stretch When greater than 0, the particles stretch along the travel axis,
depending on their speed. Specifically, the Stretch value specifies the percent
of their length per each unit of the Speed setting (in the Particle Motion group).
Thus, if you set Stretch to 2 while Speed is set at 10, the particles are stretched
20 percent longer than their original size along the axis of their travel. This
spinner is available only when you choose Direction of Travel/Mblur.
NOTE For best results when using Stretch, you should also assign the Particle
MBlur map as an opacity map of the material assigned to the particle system.
User Defined Uses a vector defined in the three X, Y, and Z axis spinners.
X/Y/Z Axis Specifies the spin vector of the X, Y, or Z axis, respectively. These
spinners are available only when User Defined is chosen.
Variation The amount, in degrees, by which the spin axis of each particle
may vary from the specified X Axis, Y Axis, and Z Axis settings. This spinner
is available only when you choose User Defined.
Interparticle Collisions group
These options enable collisions between particles, and control how the
collisions occur. Note that this involves intensive calculation, particularly
when large numbers of particles are involved.
Enable Enables inter-particle collisions in the calculation of the particle
movements.
Non-Event-Driven Particle Systems | 3065