Quick start guide
Turn on physics interpolation: Project Settings > Physics > Common > Physics Interpolation
Make sure you move objects and run your game logic in
_physics_process()rather than_process(). This includes moving objects directly and indirectly (by e.g. moving a parent, or using another mechanism to automatically move nodes).Be sure to call Node.reset_physics_interpolation on nodes after you first position or teleport them, to prevent "streaking".
Temporarily try setting Project Settings > Physics > Common > Physics Tick per Second to 10 to see the difference with and without interpolation.