Whip tail

A happy tail swish that starts at the base and travels down the tail, so the tip whips and curls behind the body. The ears flop with it and the body bounces.

Use it in a cartoonOpen it in the block editorThe pack file (JSON)

What it is for

Whip tail is for animals: a dog that is pleased, a cat that is about to pounce, the monster showing off. The tail is drawn in four segments, and the swish is a wave that moves down them, so it shows the chain of bones inside. On the person and the kid there is no tail at all, so they get the bounce and floppy hair and ears where they have them. The bird's short tail is one piece, so it swings as a whole with the swish, with no curl down it.

The principle it shows: overlapping action, or drag

When the base of a tail moves, the tip follows a moment later, then the tip is still swinging when the base turns back. Animators call this drag or overlapping action: the parts of a chain move one after another, not all at once. Here every segment of the tail plays the same swing, each 0.09 seconds later than the one before and a little bigger, which is what makes the tip whip.

The program, line by line

when it starts
  look happy
  swish tail 50° · every 0.7 s · lag 0.09 · each × 1.1
  flop ears 14° · every 0.7 s
  bob 3 · every 0.35 s
  let the hair follow the body × 0.8

• when it starts and look happy — the face changes to happy.
• swish tail 50° · every 0.7 s · lag 0.09 · each × 1.1 — the swish. The 50 degrees is the whole tail's swing, shared between its four segments; one full swing takes 0.7 seconds; each segment starts 0.09 seconds after the one closer to the body (lag), and swings 1.1 times as much (each × 1.1), so the swing grows toward the tip.
• flop ears 14° · every 0.7 s — the ears swing 14 degrees in time with the tail, and because ears are chains too, their tips flop a little after their bases.
• bob 3 · every 0.35 s — a quick small bounce of 3 pixels, twice in each 0.35 seconds.
• let the hair follow the body × 0.8 — the hair lags behind the bounce on a spring.

Try this

1. Make the wave take 0.25 seconds to reach each segment instead of 0.09. The tail now curls slowly like a cat's when it is watching something, a long S-shape rolling down to the tip.

   In the program: swish · lag 0.09 → 0.25

2. Swish 100 degrees instead of 50. The tail now lashes from side to side, angry rather than happy, and the tip flicks hard at the end of every swing.

   In the program: swish · deg 50 → 100

How it differs from Happy wag and Floppy hop

Happy wag turns the whole tail at its base, a fast, stiff wag with no curl. Floppy hop lets the tail follow a hop on a spring instead of swinging it on purpose. Whip tail is the one that sends a wave down the tail.

Works on

c4c:beh:whip_tail · version 1.0.0 · CC0 (public domain) · by Jabbertoon