Since quaternions are not so simple, I tried angle and rotation.
Thereby I get quite similar flight positions, which are partly not correct. In the console you can check better what happens with this method.
It shows that the angle is always positive and thus the relative position of the vectors is not taken into account. To see this better, I made the trajectory a bit more complicated.
See MoveAlongCurve06
Conclusion: One must make a case distinction.
Or is there a simpler solution using three.js methodes?
UPDATE:
No case distinction, just a better formula. I had already forgotten that I had this calculation 2019 in an example.
Math.atan2( )
See Addon to create special / extended geometries - #6 by hofk
A better solution see .setRotationFromMatrix( ); - what causes the mirroring and thus the flickering?
and
BeginnerExample
// … step 15: matrix, move along room curve
beeFlight( );
Related: [Solved] Help with wrong position meshes along a curve