[Bullet] move_and_slide is unstable with bullet physics.

[EMBYRDEV]

Godot version

3.3.2.stable

System information

Windows 10

Issue description

It appears that something is wrong with either is_on_floor (I have tried using it before and after calling move_and_slide) or move_and_slide itself with the Bullet physics engine.

In the third person demo I noticed the camera was jittering slightly soI narrowed it down to the player itself jittering. I tried several fixes in player.gd including only applying gravity when in the air and zeroing out velocity.y when you are on the ground however the only fix was to switch physics engines.

Steps to reproduce

Use of gravity with move_and_slide.

Minimal reproduction project

https://github.com/godotengine/tps-demo

See player.gd... having played around with many workarounds the only thing that worked was changing physics engine to Godot Physics.

[akien-mga]

Still reproducible in 3.5 RC 1 and latest 3.x (2e6b9ec).