Physics override not working properly when speed is set to 0 while moving

[Zughy]

Minetest version

5.2.0

Summary

Trying to set

player:set_physics_override({
              speed = 0,
              })

doesn't work properly while a movement key is held down (players slide in the last direction they were moving to). I've tried with set_velocity and set_acceleration equal to {x=0,y=0,z=0} but again no luck

Steps to reproduce

Overrides physics to 0 while moving

[ClobberXD]

Is this just how it appears to the client, or does the server actually register the player as moving? I'm betting on the former, as you mention set_velocity doesn't have an effect.

[sfan5]

The reason for this is that setting speed to zero not only prevents acceleration but also deceleration (parameters here).

I've tried with set_velocity and set_acceleration equal to {x=0,y=0,z=0} but again no luck

Note the these methods do nothing for players.

[appgurueu]

IMO not a bug as velocity should be kept. You can use player:add_velocity(vector.multiply(player:get_player_velocity(), -1)) BTW.

[ghost]

I'm inclined to agree. However, when sleeping for example, your speed is set to zero. However, now that a punching player can apply velocity to your character, there's no guarantee you'll stay situated sleeping in the bed. Just food for thought.

…

On Thu, Jun 18, 2020 at 8:43 AM Lars Müller ***@***.***> wrote: IMO not a bug as velocity should be kept. You can use player:add_velocity(vector.multiply(player:get_player_velocity(), -1)) BTW. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#10037 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFS4UYSDODPXK3NYITAQ56DRXIDWNANCNFSM4N5VQAUQ> .

[Zughy]

IMO not a bug as velocity should be kept. You can use player:add_velocity(vector.multiply(player:get_player_velocity(), -1)) BTW.

I don't agree as it's pretty unintuitive. I'd expect to have the player unable to move if I set speed = 0

[hecktest]

set/add velocity does not work for players.
Using the movement speed as a friction coefficient is a bug.

[appgurueu]

set/add velocity does not work for players.

It does (used to be called add_player_velocity though), only possible problem might be desync. As a workaround, you should probably attach the player to an invisible entity.

Using the movement speed as a friction coefficient is a bug.

true

[hecktest]

Oh, sorry, I was looking at outdated (0.4) documentation. Back in the day there was truly no way to manipulate player velocity, which was pretty frustrating.

[appgurueu]

Oh, sorry, I was looking at outdated (0.4) documentation. Back in the day there was truly no way to manipulate player velocity, which was pretty frustrating.

Back in the day modders would temporarily attach players to entities to move them :'-)

[grorp]

For backwards compatibility, we can't change the behavior of the speed physics override so that it doesn't affect acceleration (and deceleration).

Fortunately, with #11465 already merged and #13815 hopefully coming soon, you will be able to control all speed values separetely (using speed_walk, speed_climb, speed_crouch and speed_fast). These new overrides don't affect acceleration, so this issue can be solved by replacing

player:set_physics_override({
    speed = 0,
})

with

player:set_physics_override({
    speed = 1,
    speed_walk = 0,
    speed_climb = 0,
    speed_crouch = 0,
    speed_fast = 0,
    -- The following is optional and causes the player to stop immediately
    -- instead of coming to a halt more slowly.
    acceleration_default = math.huge,
    acceleration_air = math.huge,
    acceleration_fast = math.huge,
})

---

However, #13796 could still be an option to make the behavior of speed more reasonable.

[Zughy]

@grorp yes, #13796 is way easier. What you've suggested sounds like a messy hack (no offence)