Animation Upload Loop Controls

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Revision as of 01:00, 28 February 2011 by Coaldust Numbers (talk | contribs)
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The loop controls are a regular source of confusion. They work with percentages, rather than frame numbers, unlike every other animation program.

Many people also fail to understand what happens to frames before Loop In, and after Loop Out.

Working with Percentages

When calculating the percent you must type in to indicate the frame number you desire, beware that the loop controls do not consider the first frame, because it is not displayed. While this behavior would probably be expected, it is hard to keep in mind. To calculate the percentage, subtract 1 from the real frame number first.

For example, in a BVH file with 7 frames, the animation is really only 6 frames long. If we wanted the loop to start on frame 4 of the file, and end on frame 5 of the file:

Adjust Loop In Frame Value: frame 4 - 1 = frame 3

Calculate Loop In Percentage: frame 3/6 animation frames = 50.000%

Adjust Loop Out Frame Value: frame 5 - 1 = frame 4

Calculate Loop Out Percentage: frame 4/6 animation frames = 66.666%

If this strikes anyone as unnecessarily complex and error-prone, that feeling is normal.

A Diagram of the Example

BVH File Frame Animation Frame
1 Not Displayed (Reference Frame)
2 1 (Intro Frame 1)
3 2 (Intro Frame 2)
4 3 (Loop Frame 1)
5 4 (Loop Frame 2)
6 5 (Outro Frame 1)
7 6 (Outro Frame 2)

Before Loop In

Frames before Loop In, if any, will be played only when the animation starts. You could think of this as the intro of the animation.

During the Loop

Frames within the loop work like you would probably expect. When playback reaches the Loop Out frame it jumps back to the Loop In frame and continues. When the animation is stopped playback will stop jumping to the Loop In frame when it reaches the Loop Out frame.

If playback is stopped in the middle of the loop, playing will continue. It just stops treating the Loop Out frame specially.

After Loop Out

When a animation has been stopped the frames after Loop Out, if any, will be played. You could think of this as the outro of the animation.