• Adobe After Effects Expressions

  Expression works, but “doesn’t”

  Posted by Mike Nielsen on June 26, 2011 at 4:19 pm

  Hi Folks

  I have an expression that uses a slider manipulate some settings for camera z-position and zoom value…I finally got the math right – I can see the right values returned by the expression to the camera properties.
  Problem is: the result is wrong – totally different as opposed to just typing in parameters by hand…

  Any ideas?
  (Don’t have the exact setup with me just now,- left it at my office…)

  Thanks,
  Mike

  Mike Nielsen replied 15 years, 1 month ago 2 Members · 4 Replies
• 4 Replies

• 

  Dan Ebberts

  June 26, 2011 at 7:04 pm

  Hard to say. Maybe you need a layer space transform in there somewhere, if anything is parented. I’d really need to see the code.
• 

  Mike Nielsen

  June 26, 2011 at 7:09 pm

  Thanks for the reply, Dan – makes sense. I’ll update here as soon as I get to the project tomorrow…

  Kind regards,
  Mike
• 

  Mike Nielsen

  June 27, 2011 at 7:49 am

  Updating my question with some specific info:

  Setting keyframes by hand (no code whatsoever) for the camera:
  At frame 001: position: 960, 540, -2618 zoom: 800 pixels
  At frame 100: position: 960, 540, -1800 zoom: 342 pixels

  This produces the desired animation, that I was hoping to control by a slider:

  Slider: clamp(value, min=342, max=800)
  Camera zoom is pick-whipped to the slider…
  Camera Z position code: cameraOption.zoom*1.786-3228.82

  Argg, update: I now see, that I’m getting the right numbers but somehow my math is off!

  Help appreciated, thanks:o)

  Kind regards,
  Mike
• 

  Mike Nielsen

  June 27, 2011 at 11:07 am

  Fixed the problem – turns out my math was wrong after all, duh…
  Thanks…

  Mike

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