Why does async gcode driver with advanced motion planner support movement reinterpolation ?

[Jorropo]

I wonder why do we need movement reinterpolation ? And why does my machine sound so much better when I use it (/ doesn't jerk everything to death) ?

To talk about what I am using, Marlin already supports linear and S-curve acceleration.

So when this is configured even if openpnp would send a single GCODE move command (like with toolpathfeedrate), marlin would smooth it out.

Thus why is openpnp also doing some acceleration smoothing and sending reinterpolated gcode ?

To push it to the extreme closed loop control servos can implement acceleration limits based on current draw, adapting to the load on the servos in real time (not really useful for a PNP where the load is very predictable).

[Henrik Olsson]

Your Marlin based controller may support S-curve acceleration but not all controllers do. Smoothieware, for example, does not and so the advanced motion planner helps alot by sending G-code that tries to emulate what your controller does in firmware.

Why your machine sounds so much better is down to physics really.

If you drive a car and stomp on the breaks you'll feel a definitive jerk as the car comes to a halt but if you ease off of the breaks just as the car stops you'll get a much more pleasant experience. It's the same thing with your machine basically.