Falling from big enough height can push the kart through the ground

[kimden]

Whether it's a big zipper jump, or just falling down, it can happen for karts of any class.

Most notable cases happen in Messy Pond after the zipper, but I observed them on other maps (Lap Catch/Stukroche Bay, something else?) with big height too. Usually track creators discard them as "STK physics engine is bad, we cannot do anything", so I don't remember all of them.

[kimden]

Might be already fixed in 2.x, as for now I cannot reproduce it there.

[Alayan-stk-2]

Might be already fixed in 2.x, as for now I cannot reproduce it there.

Might be related to the increase in physics ticks?

Movement is not continuous, each physics frame objects move by a discrete distance. I would guess that, if the distance the kart is moving in a single frame is too big, it might move through a surface without a collision being detected. The code handling collisions with track geometry has been in STK for ages, so I haven't looked much into it.

You can change the physics FPS in a config file iirc, so perhaps try to see if with a low value like 60 or lower, the issue happens in more places or more often?

[kimden]

With 40 instead of 120, it happens far more often and in far more places, and with 480 it doesn't seem to happen at all (even if it's not as frequent for 120 too).