• Adobe After Effects Expressions

  A few fairly simple questions

  Posted by Jonathan Cutrell on June 9, 2010 at 4:13 pm

  Alright, so here’s what I am trying to do.
  I would like to set the position of a mask path as well as the anchor point of each layer based on its index; Essentially I am wanting to mask blocks of a composition/footage 10-20 times.

  After this, I will be using a combination of mosaic and linear wipe to fade rectangles from white to black – anyway, what I need is a point sample of the alpha or white value (I suppose this would be brightness). How would I sample a point’s color value? Each of these layers will be animated according to the black-white level.

  Thanks

  Todd Kopriva replied 16 years, 2 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Todd Kopriva

  June 9, 2010 at 11:38 pm

  You can use the sampleImage method to sample colors. Here’s a blog post that shows an example:
  https://blogs.adobe.com/toddkopriva/2009/07/color-sampler-using-sampleimag.html

  There are also some great examples on Dan Ebberts’s website and a few others linked to from the bottom of the Help page about sampleImage.

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  Todd Kopriva, Adobe Systems Incorporated
  putting the ‘T’ back in ‘RTFM’ : After Effects Help on the Web
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