• Adobe After Effects

  help with an expression

  Posted by Alan Tonn on September 4, 2008 at 3:45 pm

  Hello All

  I am trying to change the preset card wipe 3d pixelstorm to allow for more varied position movement. can someone help me understand this expression:

  transComplete = effect(“Card Wipe Master Control”)(“Transition Completion”);
  easeIn(transComplete, 33, 100, 5, 0)

  it is on the position x jitter amount of the preset. i have no idea what to do to get a larger range of x positions.

  Adam Mercado replied 17 years, 8 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Adam Mercado

  September 4, 2008 at 8:10 pm

  first, transComplete is a variable. A variable (or var) is a bucket for holding data. In this case it is looking at the current value of the Expression Slider (which itself is animated at default over 2 secs 0-100). So at 1 sec the value of transComplete = 50.

  With me so far.

  Then, the ease function is called which tweens from one value to another over time with an ease value (I’m guessing as it is the default for keyframe assistant) of 33%.

  easeIn(transComplete, 33, 100, 5, 0)
  In this case the transComplete var is being passed to the value parameter. The x jitter property is being tweend from 0 to 5 between 33 and 100 of the value, in this case the var associated with the Exp. Slider. Whilst the value is less than 33, there is no tweening, it is static. Once the value goes over 33 the tween begins, and is updated every frame until the value equals 100, at which point x jitter should be 0.

  Hope that helps, look at page 551 of the CS3 manual for details
  mm66

  Adam Mercado
  Influxx Media Production
  Motion Graphics & Video Post Production
  Fullerton, CA

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