This lesson explores the concept and use of Breakdown keys by utilizing them in an animated file. Breakdown keys are a special type of keyframe. Breakdown keys maintain a consistent proportional relationship in time with the "regular" keyframes that are adjacent to them. This allows for simplified approaches and greater freedom when editing the timing of an animation. As keyframes are adjusted, breakdown keys automatically update to preserve a proportional relationship over time with the edited keyframes. With the use of breakdown keys, only the "primary" keyframes need be considered when making major edits to timing as the breakdowns adjust themselves appropriately. As a simple example, imagine a ball that bounces once off the ground. The start of the ball animation occurs at frame 1 and the end at frame 30 where the ball is at its peak positions in space at both these times. The breakdown key, at frame 15 specifies the ball's position at ground level at that point in time. If the ball was determined as having to bounce twice as slowly, the only adjustment required would be to change the keyframe from 30 to frame 60. The breakdown key, by maintaining its relative position, moves to frame 30 ensuring that the ball's timing of the bounce still occurs half way through the animation.

STEP ONE Download the project file: minionAnim.ma Playback the animation to get a feel for the character's movements as some supporting motion to the animation will be added to the wings.

STEP TWO Select the wingControl joint by typing select wingControl in the Command Line entry field or in the Window > General Editors > Script Editor window (don't forget to press the Enter key on the NUMERICAL keypad if using the Script Editor). There is also a selection handle just above the character's wings which will select the wingControl joint. Rotational adjustments made to the wingControl joint will control rotation actions of both wings simultaneously due to pre-existing expressions. By setting keys and breakdowns to the wingControl joint, the character's overall motion can be enhanced and refined.

STEP THREE You will now set keys and breakdowns for wingControl. The chart below is a list of rotational values to be assigned to the wingControl joint. To set a key for the wingControl joint select Animate > Set Key under the Animation menu set. To set a breakdown go to Animate > Set Breakdown. Use the Channel Box or Attribute Editor to assign the specific rotational values. Set the following keys and breakdowns on the rotational values of the wingControl joint at the following frames: Rotate Frame X Y Z Key 200 -3.5 25 -8 Breakdown 265 -12 8 -5 Breakdown 305 0 0 -5 Key 330 -20 17 -30 Breakdown 345 4 20 -2 Key 360 -3 20 -20

STEP FOUR Notice that in the Timeslider keys appear as red ticks whereas the breakdowns appear as green ticks. Playback the animation to view the results. To edit the keys and see how the breakdowns adjust themselves accordingly, use Shift + Left Mouse Button to Drag Select just before and just after frame 330 in the Timeslider to highlight that region in time. The designated selection area will appear red in the Timeslider. With the key at frame 330 selected, move the red selection region around in the Timeslider using the Left MouseButton. To view the finished file minionAnimFin.ma file may be opened for reference. Note: If a breakdown has only a single adjacent key, it moves absolutely in relation to that key as it has no other reference key to maintain a relationship with.

CONCLUSION Breakdowns maintain their proportional relationship to the keys on either side of them. Editing a key affects adjacent breakdowns yet editing a breakdown does not effect any keys. In this way, it can be useful to set essential positional movements as keys and the more subtle refining motions as breakdowns. By doing so, the timing of the essential key positions can be adjusted while the breakdowns will maintain their relative timing to them and require no further adjustments. Also, as mentioned, the refinement of the breakdowns will not affect the keys that establish the main motion. Download the final scene to compare to your work : minionAnimFin.ma

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