Rethink character freezing logic

[Regalis11]

The way the server freezes characters when there's no inputs available from the client causes a bunch of problems and needs some improvements:

• Falling looks choppy because the character keeps freezing along the way.
• Clients can stop their character in place at will (which could easily be abused to prevent impact/fall damage).
• Limb physics are not disabled but collider physics are (in order to make it possible for projectiles etc to hit the limbs even if the character is frozen), which causes some weird-looking movement at times, particularly when climbing ladders.
• Since physics are completely disabled on the collider, it can move through walls. A frozen character outside the sub can teleport itself inside if a sub moves through it.

[juanjp600]

Perhaps the server should make predictions of the players' movement instead? If the prediction turns out to be inaccurate then we could rewind the predicted movement (obviously with a certain limit so it's not super exploitable) and recalculate the resulting position, without ever disabling the collider.

We should also look into adding in some lag compensation so weapons used by laggy clients take into account past positions of the targets, I've been getting reports of enemies being impossible to hit.

[rico6822]

What about making characters freeze every time they're ragdoll speed is low enough and unfreeze once it goes above it?

[Regalis11]

I believe the "flying by spamming the ragdoll button" issue is also cause by this.

[Rokvach]

With the upcoming improvements and improvements already implemented I don't see the point of keeping this issue open. Closing.

[Regalis11]

None of the issues have been addressed by the upcoming changes, I think this should still be kept open

[Rokvach]

@Regalis11 Is this still an issue with the newer changes?

[Regalis11]

Yes, we haven't done address these issues

[Regalis11]

Clients can stop their character in place at will (which could easily be abused to prevent impact/fall damage).

Since physics are completely disabled on the collider, it can move through walls. A frozen character outside the sub can teleport itself inside if a sub moves through it.

These 2 issues should be fixed by https://github.com/Regalis11/Barotrauma-development/commit/886a5474d2ebe37695e897d7dacac2f202374b56.

I'd consider this fixed: the current behavior is not perfect but the remaining issues are so minor I don't think reworking the character syncing logic just to fix them is worth it.

[Rokvach]

Couldn't find any issues with this, closing.