> ## Documentation Index > Fetch the complete documentation index at: https://docs.kinemation.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Bone motion extractor > This page explains how to extract bone movement into animation curves. `BP_BoneMotionExtractor` turns a bone's movement into float curves. Use it when an animation graph needs motion values without sampling the original bone again. Open the target Animation Sequence. Select **Window ▸ Animation Data Modifiers**, add `BP_BoneMotionExtractor`, and configure its settings before applying it. ## Settings ![Bone motion extractor with Curve Name, Ref Bone Name, Bone Name, Source Animation, and Sample Rate settings](https://mintcdn.com/kinemation/oyQuEkhb6OJwNgRz/images/gameplay-framework/unreal/modifier_bone-motion-extractor.png?fit=max\&auto=format\&n=oyQuEkhb6OJwNgRz\&q=85\&s=e6916e27c6b021b524542285e64fc2f8) Set the bone, curve prefix, and sample rate.
PropertyUse
`SourceAnimation`Animation to sample. If unset, the modifier uses the sequence you apply it to.
`BoneName`Bone whose transform is sampled.
`RefBoneName`Bone sampled at time zero to establish the reference transform. If empty, the source bone provides that reference.
`CurveName`Prefix added to the generated curve names.
`SampleRate`Samples per second. Use a positive value.
The extractor records the source bone's transform relative to the reference pose sampled at the beginning. It does not recalculate the reference bone at every frame. ## Result and revert The modifier writes the sampled transform channels into float curves on the target sequence. **Revert** removes the curves built from the prefix and suffixes; it does not restore older curves with those names. Use a distinct prefix when keeping other authored curves. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.