Unity-Technologies/UnityCsReference · error · ArgumentException

Allowed errors for keyframe reduction cannot be negative.

Error message

Allowed errors for keyframe reduction cannot be negative.

What it means

Thrown by the 3-arg GameObjectRecorder.SaveToClip when filterOptions.keyframeReduction is true and any of positionError, rotationError, scaleError, or floatError is negative. Keyframe reduction tolerances are magnitudes; negative values are meaningless and would break the reduction algorithm, so the guard throws ArgumentException before SaveToClipInternal.

Source

Thrown at Editor/Mono/Animation/GameObjectRecorder.bindings.cs:117

                throw new ArgumentException("FPS can't be 0.0 or less");

            if (!isRecording)
                throw new InvalidOperationException("Cannot save to clip as there is nothing to save. The method TakeSnapshot() has not been called.");

            SaveToClipInternal(clip, fps, k_DefaultCurveFilterOptions);

            AnimationUtility.onCurveWasModified?.Invoke(clip, new EditorCurveBinding(), AnimationUtility.CurveModifiedType.ClipModified);
        }

        public void SaveToClip(AnimationClip clip, float fps, CurveFilterOptions filterOptions)
        {
            if (fps <= Mathf.Epsilon)
                throw new ArgumentException("FPS can't be 0.0 or less");

            if (filterOptions.keyframeReduction)
            {
                if (filterOptions.positionError < 0 || filterOptions.rotationError < 0 || filterOptions.scaleError < 0 || filterOptions.floatError < 0)
                    throw new ArgumentException("Allowed errors for keyframe reduction cannot be negative.");
            }

            if (!isRecording)
                throw new InvalidOperationException("Cannot save to clip as there is nothing to save. The method TakeSnapshot() has not been called.");

            SaveToClipInternal(clip, fps, filterOptions);

            AnimationUtility.onCurveWasModified?.Invoke(clip, new EditorCurveBinding(), AnimationUtility.CurveModifiedType.ClipModified);
        }

        [NativeMethod("SaveToClip")]
        extern void SaveToClipInternal(AnimationClip clip, float fps, CurveFilterOptions filterOptions);

        extern public void ResetRecording();

        // Obsolete
        [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
        [Obsolete("The GameObjectRecorder constructor now takes a root GameObject", true)]

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Default all error fields to 0 (or a small positive epsilon) instead of negative sentinels.
2. Clamp each field: Mathf.Max(0f, value) before passing.
3. Validate the whole CurveFilterOptions in a helper when keyframeReduction is on.
4. If reduction is unwanted, set keyframeReduction = false rather than negative errors.

Example fix

// before
filterOptions.positionError = -1;
recorder.SaveToClip(clip, fps, filterOptions);

// after
filterOptions.positionError = Mathf.Max(0f, filterOptions.positionError);
filterOptions.rotationError = Mathf.Max(0f, filterOptions.rotationError);
filterOptions.scaleError = Mathf.Max(0f, filterOptions.scaleError);
filterOptions.floatError = Mathf.Max(0f, filterOptions.floatError);
recorder.SaveToClip(clip, fps, filterOptions);

if (filterOptions.keyframeReduction) { filterOptions.positionError = Mathf.Max(0f, filterOptions.positionError); filterOptions.rotationError = Mathf.Max(0f, filterOptions.rotationError); filterOptions.scaleError = Mathf.Max(0f, filterOptions.scaleError); filterOptions.floatError = Mathf.Max(0f, filterOptions.floatError); }

When it happens

Trigger: Setting CurveFilterOptions errors to -1 to mean 'unset'. Loading filter options from config where fields defaulted to -1. Copying values from a UI that allowed negatives.

Common situations: Serialized CurveFilterOptions with sentinel -1 for 'no value'. Editor UI sliders with no lower bound clamp. Tooling that reuses a single options struct and partially resets it.

Related errors

• FPS can't be 0.0 or less
• Binding type should derive from Unity type.
• Cannot save to clip as there is nothing to save. The method
• gameObject
• bindings must be non-null

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/e1d3622f61637f79. Report an issue: GitHub.