• Adobe After Effects Expressions

  help with particles

  Posted by Qeffects on July 13, 2005 at 6:27 pm

  I need a way to create particles or noise that I can move along either a path or move within a mask. I want to be able to control its speed and direction and concentration of particles. I have AE pro 6.5 in case someone wonders what effects I have available.
  Thanks in advance.

  Is there a plugin that would help me with this?

  Aharon Rabinowitz replied 21 years ago 2 Members · 5 Replies
• 5 Replies

• 

  Aharon Rabinowitz

  July 15, 2005 at 4:28 am

  try the effect called “CC Particle Systems 2” – It does that sort of thing.

  CC effects are from Cycore – it’s s seperate installer from the Regular AE install – on the same disk – but only for the non-educational Pro version.

  —————————————-
  Aharon Rabinowitz
  aharon(AT)yahoo(DOT)com
  http://www.allbetsareoff.com
  —————————————-
  Creative Cow Master Series DVD
  particleIllusion Fusion Volume 1
  available @ http://www.pIllusionFusion.com
• 

  Qeffects

  July 15, 2005 at 3:47 pm

  Is it possible to assign the position of the producer to a path that I draw with a bezier curve?

  Thanks,
  Q
• 

  Aharon Rabinowitz

  July 15, 2005 at 4:16 pm

  Yes.

  Create a solid layer to add the particle Effect to it.

  Add CC Particle SYstems 2

  Create another solid layer, and make a mask/path with the pen tool. It doesn’t have to be a closed mask.

  Then select the property called mask Shape and hit copy

  Then select the position property for the Particle Effect (Not the layer’s position property. This will be a property that has XY cordinates – I can’t remember the name of it – no AE in front of me.

  Paste the mask shape into this property, adn it will create the motion path for the effect point.

  This works for the position property of any effect or layer that uses XY coordinates.

  —————————————-
  Aharon Rabinowitz
  aharon(AT)yahoo(DOT)com
  http://www.allbetsareoff.com
  —————————————-
  Creative Cow Master Series DVD
  particleIllusion Fusion Volume 1
  available @ http://www.pIllusionFusion.com
• 

  Qeffects

  July 15, 2005 at 5:18 pm

  Thanks a million. Seems very logical once I tried it.
  Last question. I can tweak things so that the trailing flow stays somewhat behind the path, but is there a way to constrain the directionality of the flow so that it doesn’t spread or stray from the path.

  Perhaps I would be better off using a stroke effect combined with fractal noise or something to give me a similar effect.

  Thanks for your help!!!
• 

  Aharon Rabinowitz

  July 15, 2005 at 5:47 pm

  Try lowering the velcoity and/or raising the air resistance.

  Or try this – and this is pretty cool…

  – Create a solid layer and a layer called Null 1.

  – Give the solid layer the effect Particle systems 2.

  – Add the following expressions to the effect’s properties as follows:

  Position:

  thisComp.layer(“Null 1”).position

  Direction:

  veloc = effect(“CC Particle Systems II”)(“Position”).velocity;
  radiansToDegrees(Math.atan2(veloc[1],veloc[0])) – 90

  – Move the null around to control your particle emitter (it’s position), and the particles will be ejected out backwards from the emitter (like a rocket ship – the opposite direction from the ship is moving). You may still need to play with air resistance and velocity.

  BTW – This was adapted from something Dan Ebberts showed me. He rocks!

  —————————————-
  Aharon Rabinowitz
  aharon(AT)yahoo(DOT)com
  http://www.allbetsareoff.com
  —————————————-
  Creative Cow Master Series DVD
  particleIllusion Fusion Volume 1
  available @ http://www.pIllusionFusion.com

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