message: tweak trackball speed calc
diff: @@ -46,7 +46,7 @@ export const TrackballControlsParams = {
  speed: PD.Numeric(1, { min: -20, max: 20, step: 1 }),
  }, { description: 'Spin the 3D scene around the x-axis in view space' }),
  rock: PD.Group({
  - speed: PD.Numeric(1, { min: -20, max: 20, step: 1 }),
  + speed: PD.Numeric(0.3, { min: -5, max: 5, step: 0.1 }),
  angle: PD.Numeric(10, { min: 0, max: 90, step: 1 }, { description: 'How many degrees to rotate in each direction.' }),
  }, { description: 'Rock the 3D scene around the x-axis in view space' })
  }),
  @@ -463,12 +463,10 @@ namespace TrackballControls {
  function rock(deltaT: number) {
  if (p.animate.name !== 'rock' || p.animate.params.speed === 0 || _isInteracting) return;
  - const dt = deltaT / 4000; // normalize to 4s duration
  + const dt = deltaT / 1000 * p.animate.params.speed;
  const maxAngle = degToRad(p.animate.params.angle) / getRotateFactor();
  -
  - const f = p.animate.params.speed * Math.PI * 2;
  - const angleA = Math.sin(_rockPhase * f) * maxAngle;
  - const angleB = Math.sin((_rockPhase + dt) * f) * maxAngle;
  + const angleA = Math.sin(_rockPhase * Math.PI * 2) * maxAngle;
  + const angleB = Math.sin((_rockPhase + dt) * Math.PI * 2) * maxAngle;
  _rockSpeed[0] = angleB - angleA;
  Vec2.add(_rotCurr, _rotPrev, _rockSpeed);
  