How to create tempo automation from an audio part with complete tempo definition

I have a human-performance piano piece and I have to add backing instruments maintaining the original free tempo. I’ve adjusted the definition grid manually.

In short I need the project tempo to follow the audio, instead of warping audio to follow the project tempo.

Assuming you have have Cubase Pro then the answer is Tempo Detection.
I’m not at my Cubase computer so can’t tell you where it is exactly but I think it’s within the Project menu.

https://steinberg.help/cubase_pro_artist/v10/en/cubase_nuendo/topics/editing_tempo_and_signature/editing_tempo_tempo_detection_c.html

Assuming you have have Cubase Pro then the answer is Tempo Detection.
I’m not at my Cubase computer so can’t tell you where it is exactly but I think it’s within the Project menu.

https://steinberg.help/cubase_pro_artist/v10/en/cubase_nuendo/topics/editing_tempo_and_signature/editing_tempo_tempo_detection_c.html

I’ve tried performing this action but cubase will anaylize the audio and create the automation to follow the tempo that “cubase think should be”, rather than taking my manually mapped tempo definition grid.

I wonder that maybe cubase can’t switch between “tempo master” and “tempo slave” mode once tempo difinition is created (like what ableton does).

Sorry I misunderstood. But if you have a manually created Tempo map then Cubase should be able to follow this… I’m not at my DAW but will check when I’m back, I’ve done this before (when Cubase’s auto mapping hasn’t worked).

As to Cubase’s mapping not working (though this might not be the case with your piece) I’ve found that it’s usually a lot better than it looks…the key is to not look at some of the bizarre jumps it puts in but just to try a click with it and see if it fits.