Fix Foot Sliding in 60 Seconds with Kinetiq Editor

Foot sliding is the most common and visible artifact in AI-generated animations. Whether you're using Motion Diffusion, Mixamo, or any generative tool, chances are your character's feet glide across the ground during walk cycles. This tutorial shows you how to fix it in under 60 seconds using Kinetiq Editor — our free browser-based animation polish tool.

Why AI animations have foot sliding

Generative models like MoDi and MotionGPT optimize for pose diversity and motion naturalness, but they don't enforce ground contact constraints by default. The result: feet "skate" across the floor during weight-bearing phases, breaking immersion instantly in games and virtual worlds.

Traditional fixes require desktop software like Maya or Blender with IK constraint setups. Kinetiq Editor brings this capability to your browser with visual feedback and zero setup time.

What you'll need

• Any BVH, FBX, or GLB animation with foot sliding (free test files available on our marketplace)
• A modern browser (Chrome, Edge, or Safari — we recommend Chrome for 60 FPS performance)
• 2 minutes (seriously, it's that fast)

Step-by-step: Lock those feet

1. Launch Kinetiq Editor

Visit thirdrez.com/labs and click "Launch Editor". The editor loads instantly — no signup required for testing.

2. Import your animation

Drag and drop your animation file (BVH/FBX/GLB) into the viewport, or click the Import button. Kinetiq auto-detects bone hierarchies for:

• Mixamo rigs (automatic)
• UE5 Mannequin (select from dropdown)
• Custom rigs (manual bone mapping — takes 30 seconds)

Your character appears in T-pose. Hit Spacebar to preview the animation.

3. Identify sliding frames

Play through the animation and watch the feet. Look for:

• Skating during stance phase (foot should be planted, but slides forward/backward)
• Penetration through ground (foot goes below floor level)
• Toe drag (toes scrape the ground during swing phase)

Pause on a frame where the foot should be locked to the ground.

4. Activate foot locking

Here's where the magic happens:

1. Select the foot bone (click the ankle, foot, or toe — Kinetiq highlights lockable bones with green circles)
2. Press L key or click the Lock Foot button in the toolbar
3. A red circle appears under the locked foot, indicating it's now pinned to ground contact

The foot stays locked for the entire weight-bearing phase. Kinetiq automatically calculates:

• Contact duration (how many frames the foot stays planted)
• IK chain adjustments (knee and hip compensate for the locked foot)
• Natural transition (smooth unlock when the foot lifts off)

5. Lock the other foot

Scrub forward to find the opposite foot's contact frame. Repeat the process:

• Select foot bone → Press L → Red circle appears

Now both feet have proper ground contact. Play the animation (Spacebar) and watch the difference — no more skating!

6. Fine-tune with onion skinning (optional)

Want to visualize the motion arc? Press Ctrl+G to enable onion skinning:

• Cyan ghosts = past frames (shows where the foot was)
• Magenta ghosts = future frames (shows where the foot will be)

Adjust the ghost frame count (1-5) by right-clicking the onion skin toggle. This helps you verify that feet lock during proper weight transfer.

7. Export your fixed animation

Free users: Preview only (no export, but great for testing!)
Builder Pro ($19.99/mo): Click Export → Choose format (BVH/FBX/GLB) → Download
Freedom Tier ($49.99/mo): Same as Builder Pro + unlimited marketplace downloads

Your cleaned animation is ready for Unity, UE5, Roblox, or Second Life.

Pro tips from our animation team

• Lock early stance frames (right after heel strike) for maximum stability
• Use 2-3 lock points per foot for long walk cycles (prevents drift accumulation)
• Combine with IK rigging (press I key) to adjust hip height after locking — keeps spine natural
• Save checkpoints (Builder Pro feature) to test different lock configurations without losing work

Common gotchas and fixes

Problem: "I locked the foot but it still slides slightly"
Fix: Make sure you selected the ankle or foot bone, not the toe. Kinetiq locks the entire chain from the selected bone downward.

Problem: "The knee bends unnaturally after locking"
Fix: The original animation might have extreme hip movement. Use IK Fine-Tuning (cyan target spheres) to reposition the hip or torso, letting the knee relax.

Problem: "I can't export my fixed animation (Free plan)"
Fix: Free users get full editor access but no export. Upgrade to Builder Pro ($19.99/mo) for export + 50 marketplace downloads.

Why Kinetiq foot locking beats manual fixes

Kinetiq uses the same Cascadeur physics passes we apply to marketplace animations, but exposes it through a browser UI with real-time visual feedback. No rigging knowledge required.

Next steps: Polish beyond foot locking

Once your feet are locked, explore other Kinetiq tools to make AI motion production-ready:

• Smooth Motion Curves — Replace robotic linear interpolation with natural easing (7 presets: Ease In/Out, Bounce, Elastic)
• IK Rigging for Posing — Drag hands/feet, entire limbs follow automatically
• Onion Skinning Deep Dive — Master motion visualization for timing issues

Try it now (completely free)

No credit card, no signup wall. Just visit thirdrez.com/labs, drop in an animation, and lock those feet. 60 seconds to cleaner motion.

Got questions? Join our Discord community where animators share tips daily.

Kinetiq Editor is part of the Thirdrez platform — the same tech that powers our production-ready animation marketplace. Every animation we ship goes through foot locking, IK refinement, and physics validation before reaching customers.