ClipTidy

• The first keyframe (time = 0) is NEVER removed
• Reason: Defines the animation’s starting state

• The last keyframe is protected if it’s the only curve defining clip duration
• Example: A 2-second clip with one curve ending at 2.0s keeps its final keyframe
• Exception: If multiple curves end at the same time, redundant last keyframes can be removed

For standard animation curves (floats), a keyframe at index i is redundant if:

Middle Keyframes (not first or last):

1. keyframe[i].value == keyframe[i-1].value (exact equality)
2. keyframe[i].value == keyframe[i+1].value (exact equality)
3. Tangents between all three keyframes are “flat” (see Tangent Rules below)

Last Keyframes:

1. keyframe[i].value == keyframe[i-1].value (exact equality)
2. Tangents between the two keyframes are “flat”
3. At least one other curve maintains the clip duration

Why Exact Equality?

• No tolerance is applied to value comparison (conservative approach)
• Prevents accidental removal of visually important micro-variations
• Only tangent checking uses a tiny tolerance (0.0001) for floating-point precision

A tangent is considered “flat” if it meets any of these conditions:

1. Zero Tangent (tangent == 0.0)

   • Linear interpolation with no slope
   • Example: Linear mode keyframes with identical values

2. Infinity Tangent (float.IsInfinity(tangent))

   • Constant/Stepped interpolation mode
   • Creates a hard step between keyframes
   • Example: GameObject activation toggles

3. NaN Tangent (float.IsNaN(tangent))

   • Edge case for auto-calculated tangents
   • Rare but handled for robustness

4. Near-Zero Tangent (Mathf.Abs(tangent) < 0.0001)

   • Handles floating-point precision issues
   • Extremely small tangents that are effectively flat

Both tangents must be flat:

• outTangent of previous keyframe
• inTangent of current keyframe

For object reference curves (sprites, materials, etc.):

Middle Keyframes:

1. keyframe[i].value == keyframe[i-1].value (same object reference)
2. keyframe[i].value == keyframe[i+1].value (same object reference)

Last Keyframes:

1. keyframe[i].value == keyframe[i-1].value (same object reference)
2. At least one other curve maintains the clip duration

Note: Object references have no tangents, so only value equality matters

No. ClipTidy uses conservative detection rules and only removes keyframes that provably don’t affect visual output. Use Simulate mode first if concerned.

Yes. All changes are registered with Unity’s undo system (Ctrl+Z / Cmd+Z).

Likely due to non-flat tangents. Even with identical values, custom tangent curves can create visual motion.

Currently hardcoded to 0.0001f.