Unlike other layer-based compositing software, a layer in Autograph doesn't have any IN or OUT points. The existence of a layer is managed by the Visibility keys, accessible in the Dope sheet part of the Timeline.
This parameter can be animated, just like any other parameter. It can only have two states, ON or OFF, which cause the layer to appear, disappear, and reappear several times on the same line.
Although this may make you think of clips from an editing software visually, it's not the same. If you temporally offset a layer, which will modify its Time offset parameter, all of the visibility keys will also move.
By default, when you add a layer in a composition, two visibility keys are created:
- If the source referenced by the layer has a specific range, like for movies or image sequences, a first visibility key will be added (ON) at the first image, and a second one (OFF) at the last image.
- If the source doesn't have a range, like in the case of a still image, a Generator, or even if there's no source at all (like when you add a Null layer to the composition), the two visibility keyframes will be added at the beginning and the end of the current composition.
The state of the last visibility keyframe will define the visibility of the layer to infinity. To give you an example, let's add a 2-second movie to a 10-second composition:
Two visibility keyframes have been created:
- One at the first frame of the composition (0 seconds)
- One at exactly 2 seconds.
If the last visibility key is set to OFF, the layer will be invisible from this point to infinity.
Now, let's delete this second and last keyframe:
The last (and only) existing key is set to ON. As you can see, the layer now exists infinitely. If your source is loopable and you’ve set the reader’s After parameter to Loop, that's the perfect trick to have a loopable logo or background, without worrying about its duration.
If you delete all keyframes, the parameter’s visibility state in the stack will define the layer's entire existence.
Visibility keys can be used in correlation with the overall visibility eye, accessible in the layer’s main line.