Len Rig script links the prepared squash-and-stretch animation into a flexibly controlled animation. For this rig, you need to use the Length Rig Controller.
The rig is based on the morphing of prepared keyframes, what we call states. This interpolation depends on the distance between the two-layer controllers.
The rig performance depends on the number of properties, especially the number of points in the Path. Try to make your illustrations optimized. Delete all unnecessary points.
For this rig, you need Length Rig Controller , which you can find on the plus button, left from the Len Rig Button.
<aside> ⚡ SYNERGY Slider and Len Rigs can work together. After creating all states and adding Len Controller, you can select all layers and click Slider Rig. All selected properties would link to the new Slider, and the Len Rig will be added. Also, for this rig, we change the 3-2 method to 2-2 due to the changes in interpolation mechanics.
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Our script has a ton of cool features, but it needs some time and practice to understand where you can implement it and how.
So let’s start with the fasters and most effective methods.
In other words, make three keyframes, where the first would be the Squash state, and the second keyframe would be the Stretch state. For a start, it’s enough, the third keyframe could be an extra stretch, but you could just copy the second keyframe on it.
Make sure that the beginning of the layer is always located in the same place where the start controller is. The end controller could mismatch with the shape. It's okay.
Select the layers with keys and any controls layers and press the Length Rig.