Animation Flickering Issue with Cinema 4D to GLTF Export

Based on your description of flickering in skinned animations when exported from Cinema 4D to GLTF and viewed in Three.js, this appears to be an issue with animation interpolation or keyframe data.

Possible Causes and Solutions

1. Keyframe Interpolation: Three.js and Cinema 4D might be using different interpolation methods between keyframes.

2. Animation Sampling Rate: The animation might need to be exported with a higher sampling rate to capture the smooth motion properly.

3. Quaternion vs. Euler Rotations: Three.js typically uses quaternions for rotations, while Cinema 4D might be using Euler angles, causing conversion issues.

4. Animation Mixer Settings: You might need to adjust the animation mixer settings in Three.js.

Suggested Approaches

Try implementing an AnimationMixer with specific settings:

JAVASCRIPTCopied
// Create an animation mixer
const mixer = new THREE.AnimationMixer(model);

// Get the animation clip
const clip = gltf.animations[0];

// Play the animation with specific settings
const action = mixer.clipAction(clip);
action.setLoop(THREE.LoopRepeat);
action.clampWhenFinished = true;
action.play();

// Update the mixer in your animation loop
function animate() {
  requestAnimationFrame(animate);
  
  // Update the mixer with the time delta
  mixer.update(clock.getDelta());
  
  renderer.render(scene, camera);
}

You might also try adjusting the export settings in Cinema 4D:

1. Ensure you're baking the animation at a sufficient frame rate
2. Try exporting with quaternion rotations if that option is available
3. Check for any optimization settings that might be reducing keyframe data

If the issue persists, you might need to explore using the AnimationUtils class to optimize or modify the animation data after loading.

Since this appears to be a specific issue with the export/import process between Cinema 4D and Three.js, you might also consider posting your specific files to the Three.js forum for more targeted assistance from the community.