To give a little bit more information, the actual number isn't all that important. Depending on your use case, you'll get 64 or less, after you shave off rotations.
We do the entire process automatically, by taking the bit layout of each tile, and then passing it through a series of 8 transformations. If the transformed masks match any of the existing defined masks, we know we have a duplicate. In our case, we're specifically building stylized architecture, and to that end, some configurations just don't make sense.
To elaborate on the transformations, here's a snippet from our source code documentation
// Transformations
// We need to check the rotated and flipped duplicates
// Bools map to two "floors" of a 2x2x2 3d group of objects this way
// _____
// \0 3\
// \1___2\
// _____
// \4 7\
// \5___6\
//
// Flipping is just swapping of 0-1, 2-3, 4-5 and 6-7
// For rotation, since bools make up two circularly mapped "floors", a simple CCW rotation by 90 degrees looks like this:
// _____ _____
// \0 3\ \3 2\
// \1___2\ -> \0___1\
// _____ _____
// \4 7\ \7 6\
// \5___6\ -> \4___5\
In regards to the byte array, there's a bit of detail I think you might be missing. We have a number of volume configurations, that define a tileset using a byte mask. The world is then made up of a series of (points), (or voxels) in 3d space. In order to generate the final geometry, we look at each series of world (points) and place a (spot) mesh that is determined by checking that byte, against our tileset's bytemasks. When we move to the next (spot) we offset a bit in world space, and the neighboring (points) will be a part of the new (spot's) volume. That is what ensures all meshes are completely smooth and contiguous, as they are just made up of the intersection of all neighboring points.
Here is my lovely programmer art as an explanation :D Just expand that into all directions / axis
X = (point)
0 = (spot)
X-X-X ->
|0|0| ->
X-X-X ->
|0|0| ->
X-X-X ->
For some additional context / research. We are using an extrapolation of the algorithms used in marching squares, on 3d space.
https://en.wikipedia.org/wiki/Marching_squares(slightly less programmer art explanation)

We are of course ignoring the step where we interpolate to get a smooth surface. Unless we felt like doing some ridiculously fancy procedurally generated smoothly rounded buildings. Which would also make damage a massive problem to implement. Maybe we'll save that for version 2.0
Always happy to answer any additional questions you may have.
Fun techincal stuff aside! In our lore, the world has very little fossil fuels accessible, due to the number of surface impacts that have happened. Because of that, they're a fair bit ahead of us in terms of power generation and robotic technology. The mechs use a compact reactor that's underneath the pilot capsule in the back. From there, the joints are a series of high powered electromagnetic links inside the couplings. They're an extrapolation on currently available Axial Flux Motors. I should do some illustrations to show the internal workings of them, and where all the parts are located. Just need to find the time to do so! Haha
An array of these motors are going through the joint pivots. Bugatti is using them to drive one of their cars and it can put out over 1500HP. So it's not a stretch you could make them very powerful when running off a fusion reactor.

To clarify, what part of the animations isn't meshing? I know there's a lot of polish yet to be done there, but I'm curious what it is that stands out to you. Got to make sure I'm not missing something i haven't accounted for already
