A single vector can indicate a direction but, if you imagine, your node can roll without changing that vector - therefore the vector alone cannot define a quaternion. If you have two vectors, then you can calculate the third (product) from them and use the .fromAxes method to get a quaternion.

You should bear the following points in mind when considering the above paragraph.

Quaternion has a lookAt method, but you need to specify an up vector.

Ah nice! Exactly what I needed. Thanks ^_^

Alric said:

bear the following points in mind

Hmm, in my case, I'd also add:
- Read the javadoc for the methods.
I couldn't get it why lookAt (1,0,0), (0,1,0) made me look at (0,0,1). Makes sense when reading javadoc...

It computes the rotation to transform the z-axis to point into 'direction'