Motion Cleanup & Foot Locking

Motion Cleanup & Foot Locking

Module: Animation · Category: Motion · Tool ID: MotionCleanupFootLocking

A three-tab cleanup pipeline for mocap and authored animations. Foot Analysis loads an AnimSequence, samples foot bone velocities, and detects contact frames. IK Lock Curves generates IK lock curves on the analyzed clip with configurable blend time and IK type. Batch Processing runs the same workflow across a folder of AnimSequences in one pass.

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When to use it

• Cleaning up raw mocap walk/run cycles where feet visibly slide on the ground
• Generating IK lock curves consistently across an entire animation set without hand-authoring each one
• Preparing a movement clip for a Two-Bone IK / Pose Warping / Full Body IK setup
• Batch-processing a folder of locomotion clips after a mocap session

When not to use it

• Don’t use this for hand-keyed animation — they typically don’t slide
• Don’t expect this to replace cleanup in your DCC — it generates lock curves that an IK system reads at runtime, it doesn’t bake the cleanup into the source clip

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Opening the tool

1. Open the EQLabs Hub and search for Foot or Motion Cleanup (or browse to Animation → Motion)
2. Click the tool card
3. Use the tab bar to pick Foot Analysis, IK Lock Curves, or Batch Processing

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Tab 1 — Foot Analysis

Sample foot bone velocities and detect contact frames.

Interface

Field	What it does	Default
AnimSequence picker	Drop the clip to analyze	(empty)
Left Foot Bone	Bone name for the left foot	foot_l
Right Foot Bone	Bone name for the right foot	foot_r
Velocity Threshold	Velocity below this counts as contact (cm/s)	5.0
Analyze button	Walks the clip, samples velocities, builds contact ranges
Stats block	Frame count, duration, detected contact count
Contact ranges list	Per-range row: foot name, start frame, end frame, average velocity

Workflow

1. Drop an AnimSequence into the picker
2. Confirm the foot bone names match your skeleton (defaults are UE4/UE5 Mannequin)
3. Tweak Velocity Threshold — 5.0 cm/s works for most walk cycles, drop to 1.0 for slow idle clips
4. Click Analyze

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Tab 2 — IK Lock Curves

Generate IK lock curves on the clip analyzed in Tab 1.

Interface

Field	What it does	Default
Lock Blend Time	Blend time at the start/end of each lock range (seconds)	0.1
IK Type	Target IK system: Two-Bone IK, Pose Warping, or Full Body IK	Two-Bone IK
Preview Lock Curves button	Updates the preview text without writing to the asset
Generate Lock Curves button	Writes the IK lock curves to the analyzed AnimSequence
Preview block	Text summary of what will be generated

IK type behavior

Type	What it produces
Two-Bone IK	Standard IK_LockL / IK_LockR float curves clamped to [0, 1]
Pose Warping	Curves shaped for UE’s Pose Warping node consumer
Full Body IK	Curves shaped for FBIK consumer

Workflow

1. Switch to this tab after running Tab 1’s analysis
2. Pick the IK type that matches your AnimBP setup
3. Adjust Lock Blend Time for smoother transitions (0.1–0.2 is typical)
4. Click Preview Lock Curves to see what would be generated
5. Click Generate Lock Curves to write them to the AnimSequence

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Tab 3 — Batch Processing

Run the analysis + lock-curve workflow across an entire folder.

Interface

Field	What it does	Default
Batch Scan Path	Folder of AnimSequences to process	/Game
Scan Folder button	Walks the folder, populates the list
Process All button	Runs Foot Analysis + Generate Lock Curves on every included row
Batch list	Per-clip row: asset name, frames, duration, include checkbox

Workflow

1. Set Batch Scan Path to the folder containing your locomotion clips
2. Click Scan Folder
3. Untick any clips you don’t want processed (e.g., upper-body-only animations)
4. Click Process All — every included clip is analyzed and gets lock curves generated

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Settings reference

Foot Analysis tab

Field	Default
Left Foot Bone	foot_l
Right Foot Bone	foot_r
Velocity Threshold (cm/s)	5.0

IK Lock Curves tab

Field	Default
Lock Blend Time (s)	0.1
IK Type	Two-Bone IK

Batch tab

Field	Default
Batch Scan Path	/Game

Settings are persisted to [Project]/Saved/EQLabs/Settings/MotionCleanupFootLocking.json.

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Output

• In-place modification — Generate Lock Curves writes IK lock curves to the AnimSequence’s curve track
• Undo — wrapped in ScopedTransaction. Ctrl+Z reverts; batch is one undo step
• No source replacement — original animation data is preserved; lock curves are added alongside

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Tips & gotchas

• Foot bone names matter — non-standard skeletons (Mixamo, custom) won’t have foot_l / foot_r. Update the bone fields before analyzing.
• Velocity Threshold tuning — too high and you’ll miss legitimate contacts; too low and slow idle clips look like everything is “in contact”. Start at 5.0, adjust based on first results.
• Lock Blend Time of 0 makes IK pop — keep at least 0.05–0.1 for natural-looking transitions.
• Batch Process is destructive in the sense that it adds curves to source assets — re-running on already-processed clips will replace the previous curves. That’s usually the right behavior, but worth knowing.
• Save All afterward — curve writes are in-memory until saved.

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Related tools

• Animation Auditor — Curves tab can later strip the generated lock curves if you change your mind
• Skeleton Inspector & Rig Shortcuts — Skeleton Analysis tab tells you which naming convention your foot bones follow

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