When you do an uvmap of a mesh usually some vertex are unwrapped to more than a single location, see image below
https://googledrive.com/host/0BwOEIhbHMKaFQmJsUGlFaTNZS2s#.png
So, my question is: how does jme handle that? Does it just duplicate the vertex or what?
If a vertex has more than one texture coordinate for the same texture then generally JME should see that as two different vertexes… but ultimately it depends on the ‘asset path’ that you are using… though I guess both ogre and direct .blend import should handle that.
Did you try it?
Sure they both handle that, but my problem wasn’t concerning an assetloader.
I’m implementing a mesh splitting algorithm so i have to rebuild the triangles that are splitted and I came this doubt.
Thanks 
Yeah, in tools the “vertex” tends to be just the location and it can be shared across various attributes.
In OpenGL, (and thus JME) a “vertex” is actually the unique collection of all of the things: position, texture coordinate, normal, etc… Those all become vertex attributes (even position, really) and so if you need more than one of a normal or tex coord for some “position” then it is a different “vertex”.