Can I use motion capture data in Blender?
Importing Motion Capture Data
Blender supports BVH (Biovision Hierarchy) natively via File > Import > Motion Capture (.bvh). Other formats like FBX can be imported if they contain skeletal animation. For CSV or custom formats, you may need add-ons or scripts.
Once imported, the motion data appears as an armature with keyframes. You can play it back and inspect the motion. Note that the skeleton hierarchy may differ from your character's rig, so retargeting is often needed.
- BVH is the most common mocap format for Blender
- FBX from mocap systems also works
- CSV requires custom import scripts
- Imported data is usually on a separate armature
Retargeting to Your Character
To apply mocap to your character, you need to map the bones of the mocap skeleton to your rig. Blender's built-in Retargeting add-on (available in 2.8+) or third-party add-ons like Rokoko Studio Live can help.
The process involves creating a mapping between source and target bones, then baking the animation onto your rig. You may need to adjust bone rolls and rest poses to avoid distortion.
- Use Blender's Retargeting add-on or Rokoko
- Map bones by name or manually
- Bake the animation to your rig after retargeting
- Adjust rest poses for best results
Cleaning and Enhancing Mocap
Raw mocap data often has noise, foot sliding, or missing markers. You can clean it up in Blender's Graph Editor or use filters like Smooth in the F-Curve modifiers.
For foot contact, you might add IK constraints and adjust the feet to stay planted. You can also blend mocap with hand-keyed animation for better control.
- Smooth curves to reduce jitter
- Fix foot sliding with IK or manual keys
- Use NLA editor to blend multiple takes
- Consider add-ons for advanced cleanup
Common mistakes
- Assuming mocap data will perfectly fit your character without retargeting.
- Ignoring scale differences between mocap skeleton and your rig.
- Not cleaning up foot sliding, which breaks realism.