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SpringsMaterial 3

Material 3 Standard default spatial

Its damping ratio is 0.9, against 0.8 and 0.6 in the Expressive scheme. Stiffness 700, damping 47.62 and mass 1 give a damping ratio of 0.9, so the spring is underdamped. It settles to within 0.1% in 0.32 s. It passes the end value by up to 0.2% at 0.272 s and crosses it 1 time.

Demo

Progress against time. The time axis runs 0 to 0.32 s, the settle time.0100.51progress50%90%
Dashed: a straight line. The dot and the line move with the box on the right.
Material 3 Standard default spatial
linear

Both boxes take 0.32 s. Playing at 0.25× speed.

Your system asks for reduced motion, so nothing plays. The chart shows the whole move.

Code

A spring has no fixed duration, so the CSS takes the settle time (320 ms) and a linear() string that follows the spring.

css linear()
transition: translate 320ms linear(0, 0.0053, 0.0197, 0.0417, 0.0696, 0.1022, 0.1382, 0.1768, 0.2171, 0.2583, 0.3, 0.3416, 0.3826, 0.4229, 0.462, 0.4998, 0.5362, 0.571, 0.6041, 0.6355, 0.6652, 0.6931, 0.7194, 0.7439, 0.7668, 0.7881, 0.8078, 0.8261, 0.843, 0.8586, 0.8729, 0.886, 0.898, 0.909, 0.9189, 0.928, 0.9363, 0.9437, 0.9505, 0.9565, 0.962, 0.9669, 0.9713, 0.9752, 0.9787, 0.9818, 0.9846, 0.987, 0.9891, 0.991, 0.9927, 0.9941, 0.9954, 0.9964, 0.9974, 0.9982, 0.9988, 0.9994, 0.9999, 1.0003, 1.0006, 1.0009, 1.0011, 1.0012, 1.0013, 1.0014, 1.0015, 1.0015, 1.0015, 1.0015, 1.0015, 1.0015, 1.0014, 1.0014, 1.0013, 1.0013, 1.0012, 1.0011, 1.0011, 1.001, 1);
web animations api
el.animate({ translate: ['0 0', '240px 0'] }, { duration: 320, easing: 'linear(0, 0.0053, 0.0197, 0.0417, 0.0696, 0.1022, 0.1382, 0.1768, 0.2171, 0.2583, 0.3, 0.3416, 0.3826, 0.4229, 0.462, 0.4998, 0.5362, 0.571, 0.6041, 0.6355, 0.6652, 0.6931, 0.7194, 0.7439, 0.7668, 0.7881, 0.8078, 0.8261, 0.843, 0.8586, 0.8729, 0.886, 0.898, 0.909, 0.9189, 0.928, 0.9363, 0.9437, 0.9505, 0.9565, 0.962, 0.9669, 0.9713, 0.9752, 0.9787, 0.9818, 0.9846, 0.987, 0.9891, 0.991, 0.9927, 0.9941, 0.9954, 0.9964, 0.9974, 0.9982, 0.9988, 0.9994, 0.9999, 1.0003, 1.0006, 1.0009, 1.0011, 1.0012, 1.0013, 1.0014, 1.0015, 1.0015, 1.0015, 1.0015, 1.0015, 1.0015, 1.0014, 1.0014, 1.0013, 1.0013, 1.0012, 1.0011, 1.0011, 1.001, 1)', fill: 'both' });
vawe
import { spring, springDuration, springLinear } from '../../core/motion/springs.js';

const k = 700, d = 47.62;

// per-frame code (window.seek, vawe.onFrame): t is seconds since the move starts
const x = 240 * spring(t, k, d);

// CSS and Web Animations: 320 ms, the linear() string above
el.animate(
  { translate: ['0 0', '240px 0'] },
  { duration: springDuration(k, d) * 1000, easing: springLinear(k, d), fill: 'both' },
);

Numbers

Stiffness
700k, with mass 1
Damping
47.62d, with mass 1
Damping ratio
0.9underdamped
Settle time
0.32 swithin 0.1% of the end
Overshoot
0.2%peak at 0.272 s
Crosses the end
1time
50% of travel
0.061 s19% of the settle time
90% of travel
0.129 s40% of the settle time
Natural frequency
26.46 rad/ssqrt(k)
Ring period
0.545 sone swing of the overshoot
Peak speed
3.34xtimes the average speed
linear() points
81within 0.13% of travel

Computed with spring() and springDuration() from core/motion/springs.js. The settle time is the last moment the spring is more than 0.1% away from the end value; a library stops its own spring by its own rest thresholds, so its clock can run shorter.

Source of the numbers

Material 3androidx main at 9adbcd8 (compose material3 1.6.0-alpha01)
damping ratio 0.9, stiffness 700 (MotionScheme.standard().defaultSpatialSpec())StandardMotionTokens.SpringDefaultSpatialDamping (0.9) and SpringDefaultSpatialStiffness (700)

Conversion: Stiffness is used as it is with mass 1 (SpringSimulation takes the natural frequency as sqrt(stiffness)). damping = 2 x dampingRatio x sqrt(stiffness), the same c = 2 x naturalFreq x dampingRatio that SpringSimulation.getAcceleration uses.

The four closest curves in this set, by the average gap between the two springs over their first seconds. A gap of 0.01 is invisible; 0.1 is a different feel.

More springs