| curve | 要查询的曲线。 |
| index | 关键帧索引。 |
TangentMode Returns the tangent mode.
Retrieves the left tangent mode of the keyframe at a specific index.
The Curve Editor uses the keyframe tangent mode to automatically generate tangents.
另请参阅：AnimationUtility.GetKeyRightTangentMode、AnimationUtility.GetKeyBroken。