Blending Transformation Stages

Vince is a good looking dude, but underneath that handsome wormliness there are some technical bits that are needed to make the magic happen.
VIDEO: https://r2y.com/vid/vince-stage.mp4 1720x720 (21:9) 60fps
Vince undergoes four stages of change, with each stage comprised of two or more substages. This video shows the third stage.
Each stage involves one mesh of polygons blending between different "blend shapes", one shape per substage. This is a fun part of the process, because each substage can be sculpted and given its own coloring and texture properties. I can build a shader graph to apply these at different substages, and connect them to one slider that blends from one substage to the next.
This stage is the most complex because Vince's head needs to shift and rotate into a new, grubly position. Any "submesh" that has to be repositioned independently adds some extra work to this, and this includes Vince's eyes, teeth, and tongue. I have to carefully rotate and align these parts for each substage. Thankfully I can key these as offsets and tie them to the same slider. As I move the slider, they shift and rotate seamlessly.
Since I can key the slider in my animation graph, one single animation curve controls Vince's change through the entire stage.
The complexity of moving the skeleton inside the blend shapes without deforming them, though, is a different story, and is something wholly more technically challenging. Intensely painful, actually. I'll demonstrate my technique in a future post. (If I can improve this technique, it will drastically reduce the time it takes to produce an animation.)
One thing to notice in this video is that Vince's hair is set to "invisible", but it looks like he still has a buzz cut. Is his scalp painted? Pretty much, and there is a little shape to it. This is just a technique to make his hair look a little thicker. Notice how it fades out during this stage. This correlates with his actual hair shrinking into his head, also tied to the same stage slider.
You're pretty bendy, Vince.
Paul