How to Clean Up MoCap Data in 3ds Max: Step-by-Step Guide

1Import the QuickMagic FBX motion

1. Open a clean 3ds Max scene.
2. Choose File → Import and select the QuickMagic FBX file.
3. Use an animation-oriented FBX preset.
4. Confirm that animation import is enabled and select the intended take if the file contains more than one.
5. Keep automatic unit and axis conversion unless your studio pipeline requires a fixed override.
6. After import, verify that the character is upright, the scale is plausible and the timeline contains the complete clip.

2Inspect the complete animation before editing

Play the clip at normal speed, then review it frame by frame. Compare the animation with the original performance video so you can distinguish tracking artifacts from intentional movement.

1. Turn off Auto Key before diagnosing the source.
2. Review the motion from front, side and perspective views.
3. Mark problem frame ranges with notes or timeline markers.
4. Open Graph Editors → Track View → Curve Editor.
5. Inspect the root, pelvis, feet, hands and any joint that visibly pops.
6. Look for dense noise, isolated spikes, discontinuities and unexpected flat segments.

3Correct rotation flips with the Euler filter

Euler-angle representations can describe the same orientation with different angle values. When a track jumps across an equivalent boundary—such as from a positive angle near 180 degrees to a negative angle near −180 degrees—the character may show a visible snap even though the intended orientation changes smoothly.

1. Identify the exact joint and frame range that contains the visible flip.
2. Confirm that the affected controller uses Euler rotation.
3. In Track View, select only the affected rotation tracks or keys.
4. Run the Euler filter available for the selected Track View tracks.
5. Replay the full clip and inspect neighboring frames for new interpolation problems.

4Reduce jitter and excessive keys conservatively

Raw mocap commonly contains keys on most or all frames. Key reduction can simplify editing and remove small fluctuations, but overly high tolerances can flatten weight shifts, impacts, hand accents and other performance details.

A safe cleanup order

1. Duplicate the source animation or keep it on a separate layer.
2. Start with the visibly noisy track instead of the entire skeleton.
3. Apply conservative key reduction using the controller or Track View tools available in your version.
4. Review the result at normal playback speed and in silhouette.
5. Smooth only the remaining local noise or isolated frame ranges.
6. Undo or reduce the tolerance if timing, arcs or contact poses change.

5Fix foot sliding and root-motion mismatch

Foot sliding usually comes from a mismatch between the planted foot, pelvis motion, retargeted leg length and character travel speed. Locking the foot without correcting the root can make the knee stretch or the pelvis jerk, so both must be evaluated together.

Foot-lock workflow

1. Identify the contact, support and lift-off frames for each foot.
2. Place the floor plane at the correct height and verify the character scale.
3. Use IK controls or a world-space adjustment layer to stabilize the planted foot.
4. Keep the foot position and orientation stable only during the intended planted range.
5. Adjust pelvis or root translation so the stride distance matches the character's travel.
6. Blend into and out of the locked range to avoid visible pops.
7. Check the result from front and side views, including toe and heel contact.

6Retarget to CAT, Biped or a custom rig

Clean the worst source artifacts before retargeting, but perform final contact and silhouette corrections on the production character. Different limb proportions can introduce new problems even when the source motion is clean.

CAT workflow

1. Create or load the target CATRig.
2. Match the target's scale and reference pose to the source skeleton.
3. Use CAT's motion-capture workflow to map source tracks to the CATRig.
4. Review unmapped or incorrectly mapped limbs before applying the clip.
5. Add non-destructive adjustment layers for foot, hand, head and pelvis corrections.

Biped workflow

1. Create the Biped and match its figure to the target character.
2. Use the appropriate Biped motion-capture or BIP workflow for the source format.
3. Verify footstep extraction, scale, root orientation and limb mapping.
4. Use Motion Mixer when the production requires reusable clips, blending or transitions.

Choose the production rig first. CAT is not automatically better for every project, and Biped is not automatically obsolete. The best choice is the system already supported by the character, animation library and export pipeline.

7Add corrective motion on non-destructive layers

After retargeting, add only the corrections that belong to the final character: hand poses, prop contact, gaze direction, shoulder offsets, head motion and small contact adjustments.

• CAT: use local adjustment layers for offsets relative to the rig and world adjustment layers for world-space targets such as planted feet.
• Biped: use layers or Motion Mixer according to the established Character Studio workflow.
• Custom rigs: use additive animation layers or the studio's non-destructive control layer.

8Export and validate the cleaned animation

1. Trim the timeline to the required frame range.
2. Bake controllers, constraints and layers when the destination application cannot reproduce them.
3. Select the required animated skeleton or character hierarchy.
4. Export as FBX with animation enabled.
5. Use the frame rate, units and axis convention required by the destination pipeline.
6. Disable cameras, lights, geometry and textures when exporting motion-only data.
7. Import the exported FBX into a clean validation scene or the target engine.

Final quality checklist

• The character is upright and correctly scaled.
• The complete frame range is present.
• No visible rotation flips or joint pops remain.
• Planted feet remain stable without knee stretching.
• Root motion travels in the intended direction and at the intended speed.
• Key reduction has not removed important performance detail.
• The target rig preserves the intended silhouette and timing.
• The exported FBX works in the destination application.