A key frame is mainly defined by a time and a value, for some interpolation types, tangent/tension/bias/continuity is also used by calculating the final sampled value. Sampled values in a non-key-frame time position is interpolated by key-frames between the previous and next key-frames Value before/after the first/last key-frame are calculated by the Extrapolation class.
Get or set if the key frame is flat. Key frame should be flat if next or previous key frame has the same value. Flat key frame has flat tangents and fixed interpolation.
Gets or sets the key’s step mode. If the interpolation type is Constant, list.data[index] decides which key-frame’s value will be used during interpolation. A PreviousValue means the left key-frame’s value will be used A NextValue means the next right key-frame’s value will be used