My Scengraph contains 4 Nodes in a row. The Last Object (Leave) contains a LocalScale of (1,var,1). Now when change the var value first everything works fine. When I perfom a rotation of the root node, so that the Worldvector of my Object is (0,1,0), the changing of var seem to effect the Position as well. The Object is stretching differently, and it is changing its centered Position.
If You want Your model scaled uniformly then use the .setLocalScale(float).
The .setLocalScale(Vector3f) should do the same if You do setLocalScale(new Vector3f(var, var, var))
But it still souldn't change position i think ? are You sure to change the scale of the leave geometry ? and not above that ?
Have a look at Your geometry too if it is centered properly.
is your object a loaded model? maybe your model isn't centered itself ( the vertices have an offset to the local (0,0,0)) . in this case, scaling it would look like the model changed its position (i suppose - but i'm not sure about this). in such a case you would have to save the model centered along the axes from the program where you usually edit it.