2009

Script rollout
This rollout lets you apply a script to the particle system at each integration
step, as well as after the last integration step of each frame you view. Use an
Every Step Update script to set up history-dependent properties, and a Final
Step Update script to set up history-independent properties.
Every Step Update group
The Every Step Update script is evaluated at the end of each integration step,
after all actions in the particle system are evaluated, and all particles are finally
in their respective events. When, for example, you are setting up Material ID
according to a particle index, it is important to be sure that particles are not
about to jump to another event.
When you set up history-dependent properties, such as speed, it is important
to do that at every integration step, because otherwise the final position would
be quite different.
Enable Script Turn on to cause a script in memory to be executed at each
integration step. You can modify this script by clicking the Edit button, or
load and use a script file with the remaining controls in this group.
The default script modifies particle speed and direction, causing particles to
follow a wavy path.
Edit Click this button to open a text-editor window with the current script.
When Use Script File is off, this is the default Every Step Update script
(3dsmax\scripts\particleflow\example-everystepupdate.ms). When Use Script File
is on, this is the loaded script, if you've loaded one. If you haven't, clicking
Edit displays the Open dialog.
2836 | Chapter 14 Space Warps and Particle Systems