DOCS/Drivers

Spin

Behaviors

Constant rotation at a fixed rate, forever.

Spin ramps a property at a steady rate. On rotation, that is a constant turn. It never eases, never stops, and never needs a second keyframe.

It is the simplest driver in the set, and it removes a surprising amount of keyframe bookkeeping — a loading spinner is one control instead of two keys and a loop expression.

Try itSpin

Rate90/s

Target propertyrotation

Copies1

This stage calls the shipping driver — the same `evaluate()` the editor runs each frame.

When to reach for it#

Loaders, gears, fans, records, and anything that turns continuously.
Endless scrolling backgrounds, by targeting position.
Driving a Repeater ring so the whole array turns.

How it works#

The output is rate × time. On rotation the units are degrees per second, so 360 is one full turn a second and 90 is one turn every four seconds. Negative rates run the other way.

Because it is a straight ramp, it does not loop — it just keeps going. That is exactly what you want for a spinner, and exactly what you do not want if you need a seamless export loop, in which case pick a rate that completes a whole number of turns over your composition length.

Parameters#

Raterate#

Units per second. On rotation, degrees per second. 240 is a brisk loader; 20 is a slow ambient drift. Negative reverses.

Target propertytarget#

Usually rotation. On position it becomes constant travel, which paired with a Tile modifier gives you an endless scrolling background.

Recipes#

A seamless loop

Work out your composition length — say 3 seconds.
Pick a rate that gives whole turns over that length: 120°/s is exactly one turn in 3 seconds, 240°/s is exactly two.

Any rate that is not a whole number of turns over the comp length will visibly jump at the loop point.

Things that catch people out#

It does not loop on its own

Spin has no period. Only the numbers you pick make the export loop. See the recipe above.