Simple animation smoothing algorithm
An easy trick to smooth animation keyframes - 06/2023 - #Jumble
Consider the previous and next keyframe, do a linear interpolation to create an "intermediate" keyframe. Then do a linear interpolation between this newly created keyframe and the existing keyframe in the middle (or replace it altogether)
t = (pose.secs - prevPose.secs) / (nextPose.secs - prevPose.secs); lerpPose = Lerp(prevPose, nextPose, t); res= Lerp(pose, lerpPose, smoothStrength);
A more detailed version:
for (int j = 0; j < nb_smoothing_iterarions; ++j)
{
Animation<SkeletonPose> smoothed = new Animation<SkeletonPose>();
smoothed.keys.Add(_cooked.keys[0]);
for (int i = 1; i < _cooked.keys.Count - 1; ++i)
{
SkeletonPose previousPose = _cooked.keys[i - 1];
SkeletonPose current = _cooked.keys[i];
SkeletonPose nextPose = _cooked.keys[i + 1];
float parameter = (current.seconds - previousPose.seconds) /
(nextPose.seconds - previousPose.seconds);
// Lerp every joint transformations inside the pose
// Works best when the skeleton uses quaternions:
SkeletonPose predictedPose = previousPose.Lerp(nextPose, parameter);
smoothed.keys.Add(current.Lerp(predictedPose, smoothingAmount));
}
smoothed.keys.Add(_cooked.keys[_cooked.keys.Count - 1]);
_cooked = smoothed;
}
Better smoothing algorithms exists such as Savitsky-Golay filters, however, they are way more involved.
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