You can set keyframes for any animatable parameter at any time, and in any order. When you add a keyframe, the interpolation between the previous and the next keyframe is computed automatically. Setting a keyframe over another keyframe replaces the old keyframe.You can set keyframes the following ways:

• The Keyframe button in the Player controls, which only sets keyframes on marked attributes.
• The Add Keyframe button in the Tool Options.
• The Add Keyframe button in the Animation Tab.
• The Set Keyframe option list when you right-click on an attribute's value field in the tool UI or in the Composition Browser.

• The Set Keyframe hotkey (K).
  NoteWhen you use the K hotkey in the Animation Editor, keyframes are added as follows:

  • If none of the inputs of the selected node are selected, a keyframe is added at the current viewer's time for every input in the selected node (as if you selected every input in the tool).
  • If at least one input is selected, keyframes are set on the selected inputs only.
  • Every time a keyframe is set, there is no check for previous animation on inputs. This means that pressing the K hotkey will set keyframes on inputs even if the inputs were not already animated.

• The Set Keyframe for marked attributes hotkey combination (Shift + K).
  NoteThe Shift + K hotkey has the same behavior as the Set Keyframe buttons mentioned above. It will set keyframes for all the marked attributes of the currently selected tool. The K hotkey, on the other hand, can only be used in an Animation Editor context.