Which Blender Graph Editor tools clean and smooth mocap F-curves (Clean, Decimate, Bake, Gaussian, Butterworth), and what artefacts does the manual warn about?

Problem. Raw markerless curves are dense, noisy and over-keyed. Conditions. Blender Graph Editor, F-curves of an imported FBX/BVH. Method. Bake Keyframes creates a key at every frame (use before filtering so uneven samples do not skew a filter). Clean Keyframes deletes keys equal to neighbours within a Threshold and the manual says to run it after bulk keying and before hand tweaking. Decimate removes keys that influence the shape least, by ratio or by allowed error. Smooth (Gaussian) has Factor, Sigma and Filter Width. Butterworth Smooth preserves peaks and suits large data but can add a ripple when values change rapidly; lower Frequency Cutoff gives a smoother curve; Samples per Frame resamples first and should be raised to 2 for sub-frame keys such as 60 fps data in a 30 fps scene. Failure modes. Over-smoothing flattens contacts and impacts; ripple around fast changes (manual). Limitations. Manual describes controls, not recommended numbers; apply per channel and keep foot contacts separately (see C3-B752-13). Version/date. Blender manual main branch read 2026-10-23 (some details may differ from a given Blender release). Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Correction folded 2026-10-24 from C3-B764-03 (curator-reviewed discovery audit): Problem. C3-B752-11 tags 'over-smoothing flattens contacts and impacts; ripple around fast changes' as '(manual)' and says Bake Keyframes is 'use before filtering so uneven samples do not skew a filter'. The manual documents neither. Conditions. Blender Graph Editor F-curve operators. Method (what the manual says). Bake Keyframes only 'creates a keyframe at every frame'. The resampling-for-uneven-spacing step belongs to Butterworth Smooth's Samples per Frame option, which resamples before that filter runs. The only stated downside of Butterworth Smooth is a ripple effect when key values change rapidly. Treat bake-before-filter ordering and contact flattening as practitioner inference (reasonable, untested here). Failure modes. Citing the manual for contact flattening or bake ordering. Limitations. Manual main branch only; no Blender release comparison. Version/date. Manual main branch as fetched. Limitations: Read from the manual source file (reStructuredText), not the rendered site, which returned a bot challenge. Manual licence not checked. Version-specific operator names may differ. Corrected by C3-B764-03; where the correction disagrees, the correction governs. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://projects.blender.org/blender/blender-manual/raw/branch/main/manual/editors/graph_editor/fcurves/editing.rst",
      "note": "Bake Keyframes; Clean Keyframes; Decimate; Butterworth Smooth; Butterworth Smooth; Butterworth Smooth; Butterworth Smooth"
    }
  ]
}