• Adobe After Effects Expressions

  Resolving a blurred layer with expressions

  Posted by Rob Nairn on August 6, 2007 at 2:08 am

  Hi,
  I need some help with what I imagine is a really simple expression (Finding it really difficult to get my head round how expressions work!):

  I want to control the amount of blur on a layer dependent on the number of frames away from from its in point. I imagine I want to have a 25 pixel blur on the layer for the first frame then by about 10 frames in have the blur at 0.

  So rather than copy and paste keyframes to other layers at multiple points in time I want to just paste the expression once to each layer and have it sort out the timing. Is this a good thing to use expressions for?

  Thanks for your help,
  Rob

  Rob Nairn replied 18 years, 9 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Mike Clasby

  August 6, 2007 at 2:59 am

  This hack from a Dan expression seems to do what you want. It is applied to the Amount of blur (Copy the expression, Alt Click the Amount Stopwatch, then Paste) I use Fast Blur, but whatever blur you want:

  maxBlur = 25 // amount of initial blur;
  minBlur = 0 // amount of final blur;
  nFrames = 10 // number of frames to change blur;
  f = thisComp.frameDuration*nFrames;
  linear(time,inPoint,inPoint+f,maxBlur,minBlur)

  Change maxBlur, minBlur, and nFames to taste.

  If you want it to ease in a bit, I like that a little better, change the last line to:

  easeIn(time,inPoint,inPoint+f,maxBlur,minBlur)
• 

  Rob Nairn

  August 6, 2007 at 4:23 am

  That has worked a treat! Just what I was after.
  Thanks very much
  Rob

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