3d world gravity

Question

I am using drum kit to trigger and inform particle systems in
director. I want to use the hihat pedal to affect the gravity
settings of the 3d world. As it stands, when you hit a drum pad a
burst of particles flow upwards. There could be multiple particle
systems in the air when the hihat pedal is kicked so all active
particle systems will need to visibly affected by a sudden burst of
gravity . Or better still, imagine if I could kick the hihat pedal
and randomly disperse all active particle sysytems at once. Does
anyone have any ideas?
Many thanks,
Ailbhe

Answer 1

Multiplying the vector by a rotated transform may provide the results you are looking for.
on test
  v = vector(0, 0, -9.81)
  t = transform()
  t.rotate(1, 1, 0)
  put v
  -- rotate in X, Y directions
  repeat with cnt = 1 to 10
    v = t * v
    put v
  end repeat
  -- rotate back
  t.rotate(-2, -2, 0)  -- reverse rotation
  repeat with cnt = 1 to 10
    v = t * v
    put v
  end repeat
end test