• Adobe After Effects Expressions

  Change Value on Previous Keyframe in Index, not Nearest

  Posted by Jonathan Moxness on July 31, 2020 at 7:04 pm

  I have an expression on a Null slider (“Magazine control”) that I want to add 25 to the value of every time I add a keyframe to another slider on the same Null (“Magazine Reload”). Currently I have it mostly working except it’s changing when it’s closer to the next keyframe than it is to the previous, and I want it to change only when it hits the next keyframe, not when it’s closer, so I need to reference the previous keyframe instead, and I’m not sure how to do that.

  Here’s my expression currently (applied to the “Magazine control” slider effect):

  reload = effect(“Magazine Reload”)(“Slider”).nearestKey(time).index;
  Math.round(value)+(25*reload);

  I found a couple other forum posts referencing previous keyframes in expressions, but I couldn’t figure out how to translate them to my problem.

  reload = effect("Magazine Reload")("Slider").nearestKey(time).index;
Math.round(value)+(25*reload);

  Jonathan Moxness replied 5 years, 12 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  July 31, 2020 at 7:21 pm

  I haven’t tested it, but it should be like this:

  reload = effect(“Magazine Reload”)(“Slider”).nearestKey(time).index;
  if (time < effect(“Magazine Reload”)(“Slider”).key(reload).time) reload–;
  Math.round(value)+(25*reload);

  Dan
• 

  Jonathan Moxness

  July 31, 2020 at 7:56 pm

  Thank you so much Dan! Works perfect!

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