Continuous Rasterization and the Puppet Pin Tool? Possible? Questions and Problems.

> Should I just not use the puppet tool on vector layers when continuous rasterization is selected?

Short version: No. Best practice is to either size your artwork in Illustrator to the largest size that you expect needing for the animation, or to make all adjustments with Continuously Rasterize enabled and then pre-compose that layer, and apply the Puppet effect to the pre-comp.

Long version: When you apply the Puppet effect (which happens the first time you click on the layer with any of the pin tools), the Puppet effect's first step is to create a mesh based on the raster outline (alpha channel) of the layer. The deformations you make by applying and manipulating pins work by modifying this mesh. The pins sit on intersections of the mesh, and it's those intersections that determine how the mesh is sculpted. On each frame, the Puppet effect renders the mesh deformation result. This render is rasterized pixels, not vectors, regardless of the layer type. i.e., Input pixels are warped to the mesh and output pixels are returned.

The conflict between Continuously Rasterize (CR) and the Puppet effect isn't necessarily the difference between vector and raster, but that the Puppet effect only calculates the mesh that one time, when the effect is first applied. CR can cause the layer's outline to change on every frame. Thus, CR can cause the layer's pixels to mismatch the mesh that was created, and parts of your layer start falling outside the original mesh and stuff gets weird real quick.

This problem is noted commonly by After Effects artists, so we've investigated what it would take to solve this problem. It's not easy, and not something I see us changing soon due to the complexity. The crux of the problem is that the mesh that the Puppet tool creates is adaptive and based on the unique raster outline of the layer. If the layer outline changes, the structure of the mesh needs to be recalculated. If the Puppet effect did that on the fly, the pins you place could move unexpectedly. For example, if you placed a pin on your character's elbow, and then the mesh was recalculated on a later frame, the mesh point where the pin sits may not longer exist. After Effects would need to either move the pin to the closest mesh intersection, which might be in the middle of the forearm or upper arm, or maybe no useful mesh intersection would exist and the pin would just get deleted. A related problem is performance: calculating the mesh is relatively quick, but it's not something you want to have happen on every frame, it would slow down rendering performance significantly.

I hope that helps clarify.

It's just a render order problem. Puppet creates a mesh based on the alpha channel of the layer when you apply the first pin and the pin position is based on the frame size of the composition. Animate a layer from left to right over two seconds, put the CTI at one second, create puppet pin and scrub through the timeline and you'll see that the pins don't move. The mesh stays right where it was when you applied the first pin. This means you cannot animate any transforms on a layer that has Puppet Pin applied to it you have to pre-compose, then transform the pre.comp. You can collapse transformations at that time but PPin generates pixels so there's not much point in doing that.

You end up with the same problem when you try and use puppet pin on a vector layer with CR turned on. The mesh is generated on the first frame, then you move the pin and it moves the pixels, then you turn on CR and after the movement, the unchanged vector shape is rasterized. It's never going to work because you cannot transform or move the vector shape and then turn it into pixels.

In the latest release of After Effects, you can't even apply puppet pin to a shape layer or a vector layer that is continuously rasterized. You also cannot animate the position, scale and rotation of a layer that has Puppet Pin applied because the mesh is generated on the first frame.

Did you follow all of that? If you want to animate a waving hand you have to do that before you do the transform. If you want to prevent jaggy edges when you push in you should turn on CR, push or zoom in making the layer is as big as it is ever going to be in the frame, pre-compose moving all attributes, collapse transformations on the nested comp, apply puppet pin and animate the waving hand, then pre-compose the animated layer moving all attributes, position the hand in it's close up position, set position and scale or camera keyframes, then pull back and place the layer in it's starting position. That's the proper workflow.