The ‘Sine’ Bird

There’s a little bird that visits my backyard feeder, one I’d call a Sine Bird if it didn’t already have a good name: chickadee. It makes its distinctive chick-a-dee-dee-dee call, and then it flies from its branch to the feeder in a sine wave instead of a straight line. Once it’s found the perfect sunflower seed, it flies in a sine wave right back to its branch like this:

Bird flying a sine wave

You can create your very own Sine Bird (or Sine Ball or Sine Pencil or Sine Whatever) by doing this:

1. Add a png file to a slide.
2. Zoom the image out, if necessary, so it’s fairly small.
3. Place it at the far left of the screen in keyframe 1 and at the far right in keyframe 2.
4. Right-click the ‘y’ box in Pan (that’s the right-hand box of the pair) and choose “Add Modifier.” (It doesn’t matter if you do it in keyframe 1 or 2.)
5. Choose “Amount from Function” where you’ll see that the first choice is “Sine Wave.” That’s the one you want.
6. Click the preview button to see what happens. (Bird gets seasick.)
7. In Amplitude, replace 50.00 with 15.00. Notice how the representation of the wave flattens out a bit. This is the path the bird (or whatever) will follow. Preview it to see the Chickadee (or whatever) fly.

Assuming you’ve never in your life used a modifier, then congratulations! You’ve just modified an effect.

Some things to think about:

“Frequency” isn’t from a secret language that only physicists speak. It simply means how frequently something happens. In this case, we’re speaking of how frequently the wave occurs. Replace the default .50 in the frequency box with .40, then .30, then .20, and finally .10 to see it explained quite graphically.

“Amplitude” is how high and low the peaks and valleys go. The larger the number you place in amplitude, the higher the mountains and the lower the valleys.
Play like mad, adding just the sine wave to various types of motion. Don’t try any of the other waveforms until you’ve exhausted that poor Sine Bird. It’ll make it easier to use the other types of waves.

Published in: on August 4, 2010 at 5:05 pm  Comments (4)  
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