SodorScratchbuiding.com - Here's a rough proof-of-concept that I exported for your enjoyment. I intend to use this on the Bandai locomotives, but having never done 3D tracking (I've only done 2D) before, I figured I'd start out in a proven scale.
Hence, James is wearing Peter Sam's face, there are no eyes, shaders are wrong, no motion blur, etc. I figure, after 5-6 days of furious experimentation just trying to get the face to track right (thanks for nothing, Blender), I consider this one big win. Especially considering the huge 4K file (thankfully, this footage tracked perfectly - and I left it shaky on purpose. If it could track something this rough...).
I really didn't expect to wind up trying this out on James, but...hey, more James.
P.S.: Nah, this isn't Part 6 in the making.
Thanks to Nick (NorrambyBranch) for loaning the Peter Sam face. Check out his channel at:
/ @thatotherdude11