• Adobe After Effects Expressions

  adding subtle flicker

  Posted by Adam Taylor on January 9, 2009 at 11:40 am

  i want to simulate the very subtle light changes seen when looking out the cockpit of a helicopter whilst the rotors are spinning.

  I have tried playing with the opacity on the layer i need to animate, and i think the best results are to flicker from 88% to 95%.

  I tried using Wiggle(5,3) – i think (probably wrongly) that this should wiggle 5 times a second, with a range of 3 units in either direction (ie.6 units).

  It is close but not quite right…the wiggle is just a bit too random.

  Please can someone tell me a better way to impart slightly more controlled flicker than by using a wiggle?

  thanks
  Adam

  Adam Taylor
  Video Editor/Audio Mixer/ Compositor/Motion GFX/Barista
  Character Options Ltd
  Oldham, UK

  http://www.sculptedbliss.co.uk

  Adam Taylor replied 17 years, 7 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  January 9, 2009 at 2:52 pm

  How about something like this:

  freq = 5;
  amp = 3;
  base = 92;
  base + amp*Math.sin(freq*time*Math.PI*2)

  Dan
• 

  Adam Taylor

  January 9, 2009 at 2:55 pm

  thanks Dan,

  I’m beginning to wish (for the first time in 25 years) that i had actually paid attention in maths class.

  regards
  Adam

  Adam Taylor
  Video Editor/Audio Mixer/ Compositor/Motion GFX/Barista
  Character Options Ltd
  Oldham, UK

  http://www.sculptedbliss.co.uk

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