Skip to content
MotionAtelier

Wave

Wave travels from the first key to the second while swinging smoothly around the straight path between them. The swing fades to nothing at both keys, so they are reached exactly.

Wave with default parametersThe value climbs from 0 to 1 along a straight line while oscillating four times around it; the oscillation is largest in the middle and zero at both ends.
Wave, default parameters (Cycles 4, Amplitude 0.15, Phase 0°, Decay 0). Plotted from MotionAtelier 0.4.2's own curve code, outside Houdini. An illustration of the curve, not a screen capture.

Use it

Section titled “Use it”
  1. Set SHAPE ▸ Wave.
  2. In the Motion Stack tab, set Cycles, Amplitude, Phase and Decay.
  3. Preview, select the keys in Houdini, and press Commit Keys.

Parameters

Section titled “Parameters”
ControlRangeDefaultWhat it changes
Cycles0.50 to 24.00
slider to 10.00; type larger values		4.00Full oscillations across the span. Fractional values are allowed.
Amplitude-1.00 to 1.00
slider to 0.50; type larger values		0.15Peak offset from the straight line between the ends. Measured in units of the whole move: 0.15 swings up to 15 % of the distance between the two keys. Negative values swing the other way first.
Phase-180.00° to 180.00°0.00°Starting angle of the oscillation, in degrees. Shifts where the oscillation starts. 90° starts on a crest instead of on the path.
Decay0.00 to 8.00
slider to 5.00; type larger values		0.00How quickly the oscillation fades toward the end. 0 keeps the swing symmetric, largest in the middle. Higher values make it fade towards the second key.
Wave with Decay 2 and with Phase 90 degreesWith Decay 2 the oscillation is strongest early and fades before the end. With Phase 90 degrees it starts on a crest, so the first swing goes up immediately.
  • Decay 2
  • Phase 90°
Cycles 4 and Amplitude 0.15, with Decay 2 (solid) or Phase 90° (dashed). Plotted from MotionAtelier 0.4.2's own curve code, outside Houdini. An illustration of the curve, not a screen capture.

Behaviour

Section titled “Behaviour”
  • Shape. The value is the straight path plus a sine wave. The wave’s envelope is zero at both keys, so it never moves the keys themselves.
  • Accurate keys. Keys are placed at every crest and trough with their exact slope, and segments are split further until the committed curve is within 0.05 % of the move from the exact wave. The default uses 31 keys per interval.
  • Key limit. A wave uses at most 240 keys per interval. If more would be needed (many cycles at large amplitude), the best curve within that limit is used and the status line notes the wave reached its key limit.
  • Needs a move. Wave oscillates around the path between two different values. On two keys with the same value the interval is written flat; see Equal end values.

Factory recipes

Section titled “Factory recipes”
Recipe Cycles Amplitude Phase Decay
Gentle Sway 2 0.15 0° 0
Fading Ripple 3 0.25 0° 2
Offset Swing 2.5 0.20 90° 0.5
Section titled “Related”
  • Noise: irregular instead of regular variation.
  • Elastic: oscillation that settles around the end value.