• Adobe After Effects Expressions

  Converting Linear Wipe to layer space

  Posted by Julian Chojnacki on September 13, 2023 at 1:34 pm

  Hey folks!

  Just wanted to share an expression that converts the Linear Wipe’s Transition Completion percentages to layer space for continuously rasterized layers like shapes & text.

  Transition Completion:

  const { left: l, width: w, top: t, height: h } = sourceRectAtTime();
  
  const rectToPercent = (x, y) => [toComp([x, y])[0] / width * 100, toComp([x, y])[1] / height * 100];
  
  const [left, top] = rectToPercent(l - 1, t - 1);
  const [right, bottom] = rectToPercent(l + w + 1, t + h + 1);
  
  const directions = {
      0: [100 - bottom, 100 - top],
      90: [left, right],
      180: [top, bottom],
      270: [100 - right, 100 - left],
  };
  
  const angle = Math.abs(effect("Linear Wipe")("Wipe Angle") + 360) % 360;
  const [wipeStart, wipeEnd] = directions[angle];
  
  linear(value, 0, 100, wipeStart, wipeEnd);
  

  Angle:

  (Math.round(value / 90) * 90) % 360;

  For now, I snapped the angles to increments of 90° because I haven’t figured out how to interpolate between the corners yet. But for anyone satisfied with wiping left, right, up, or down – this does the trick.

  Alternatively, I made a preset that lets you wipe in & out using a single instance of the Linear Wipe effect and a single slider going from -100 to 100% (0% being center).

  Sadly Cow doesn’t let me upload .ffx files, so here‘s a link.

  Have fun!

  we.tl

  Advanced Linear Wipe.ffx

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  0wECpoZpd7.mp4 540 KB MPEG-4 - Click to view

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  Julian Chojnacki replied 12 months ago 1 Member · 0 Replies
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