Could we get players and entities on vehicles to move with them? It would be nice. And fun. And I wanna try putting a car onto a plane.

Uuuh, players already do this as of V11.2.0. There's even a JSON parameter for making it so players don't get blown off by wind shear which is specially designed with zepplins and fun car action scenes in mind.

...I tested this before posting. It wasn't working for me, unless I wasn't understanding something about how the system works. Or unless you fall off external surfaces at really low speeds.

You shouldn't. What MTS version was this in?

V11.2.0, as you said.

Odd. You wouldn't happen to have a video, would you?

Only unusual aspect about it was that I was running it in my dev environment. I'm not doing anything that should screw with MTS physics or hit detection, but I guess it's possible.

I can try to recreate and get video, sure.

Can you try in regular MC? You never know with dev what gets fouled up.

Let me check in my dev environment first. It's possible something was just wonky, or I messed up testing. If it's still an issue, I'll confirm in my normal directory.

Yeah, it looks like the issue isn't with the player not being able to stand on the hitboxes, it's with them not keeping up with the vehicle. They start falling off backwards at really low speeds. Like, "slower than walking" speeds.
https://youtu.be/sjT0N_W-BOs

What's your speed factor, and can you put an BLK/S gauge in the vehicle or give me a rough calculation of the exact speed?

Speed factor is untouched. As far as speed, it looks to be about 3.5 BLK/S.

That doesn't make sense... in the code you don't start slipping until you hit at least 5 BLK/S. Is this on a large or small hitbox?

...I have a video, don. XD

It takes a while before the falling off bit starts, but it also seems to start kinda gradually. It started way before 3.5 BLK/S, that was just the point where I couldn't easily stay standing on the wing any more.

...Also, any chance we could have it so creative mode players don't fall off moving hitboxes? It would enable fun Just Cause-style messing around.

Will investigate the slippage. That does indeed look like too much for that speed. I may need to tweak something there...

I know what this is. I'm calculating the 5 BLK/S using the un-factored speed that's internal to the vehicle, not the factored speed that the actual vehicle is moving at. This means that when I check for 5 BLK/S at 0.35 speed factor it's actually at 0.75 BLK/S. Will fix.

Awesome.

Can it be configurable? :3

Yes. But that's a separate ticket. :)

Fixed in Commit 78181d8.