Implement physics interpolation in 2D (already implemented in 3.x)

[wyattbiker]

Godot version

v3.5.stable.official [991bb6a]

System information

Mac OS X (Catalina) 10.15.7

Issue description

Have a very simple parallax background and a moving RigidBody2D. It jitters every few seconds scrolling. I am just using add_force() once to get it going.

Steps to reproduce

1. Create a new scene with Node2D.
2. Add ParallaxBackground and ParallaxLayer Texture background
3. Set the mirror to same size as Texture
4. Add a RigidBody2D with a Sprite, Camera and Collision2D
5. Check Camera2D as current
6. Add a force of 25 to Rigidbody2D
7. Run the project.

Notice that every few seconds the Spite snaps/jitters.

Minimal reproduction project

Open and click run. Watch every few (maybe 10) seconds it bounces.

ParallaxTest.zip

[lawnjelly]

Physics interpolation is not yet implemented for 2D. I'm aiming to have this working for 3.6.

Until then, feel free to try my addon which will do 2D interpolation:
https://github.com/lawnjelly/smoothing-addon

[Zireael07]

Drive by comment: I'm not certain physics interpolation is implemented in 4.0 at all (whether for 3D or 2D). Could this be clarified in docs?