Hoverboards!

They're all the rage these days.

I thought of a possibly cool "special effects" and/or gaming and/or VR rig/system that well, I'll describe it. You tell me if it's useless and stupid.

You have a kind of "board" that you stand on. If you like, exactly the dimensions of a regulation hoverboard.

It just gimbals at a single point in the neighborhood of the center of gravity with you standing on it; pretty much in the middle. It's not supposed to be difficult to 'ride' or anything like that. If anything, things that make standing on it easy and natural for all but the twistiest of ankles; practical.

Imagine a heavy metal "stalk" bolted to the floor about 8" tall, sticking straight up. It's strong, don't worry about it. It has a lubricated ball on the top ~2" in diameter (settle down). on the underside of the hoverboard there is a socket that's just the right size to accept this ball. The socket is "slick", but only enough. Like rather-tacky nylon. And it's meant to wear slowly.

You put the hoverboard on top of this stalk, lining up the ball and socket. Maybe it snaps because the socket is over-center, but only a tiny bit. It's has a "healthy" amount of friction, so you can safely stand on it if you use the handrails (look around you) and transition your weight to both feet gradually and equally.

Now, you're standing there and you can carefully pivot the board on the ball: leeeft, riiight, forward... backward.

In any number of foolproof ways, you can have a computer keep track of these "inputs".

Recall that you are on a hoverboard. So obviously you are moving forward (possibly radically fast) and you can apply leeeft and riiight and swerve back and forth as you move forward. Maybe imagine trees for reference, but don't hit any.

The computer knows with great, great precision how much left and right and up and down and it can keep a running tally of the area under the curves and all that shit. It has 100% of the information required to deduce your path down the virtual ski hill. Right? Aren't those the only inputs??

Oh, right, "centrifugal" force. Well, the computer also knows how much centrifugal force you are experiencing at any point too! And, if you'll recall from your snowboarding days, your sense is that the force is always "down"; just like an airplane or a motorcycle. You never feel centrifugal force pulling your shoulder to the left or right. You only feel more or less "down".

So, in this virtual world, given the radius of your (bodacious) curve and given your speed, the computer knows just how much you should be leaning in. Your little avatar is just standing upright.

And! So! Are! You!

Which means that not only is your avatar a reasonable facsimile of a person riding that curve, but so are you! A camera can record you and project you into the v-world and just bank you as needed. You're standing upright. Nothing weird. You are really hanging ten, good buddy.

This also means that cameras that move around to capture your awesomeness can have a sense of the force coordinates and therefore have the sense of "up" (the way the helium ballon points) and "down" (the way the air balloons point [which one is "luft"?])

The latter probably is 100% a software thing, but it's interesting to note. If you had to, you could add those coordinates "mechanically" somehow.