Loading Scenario trouble

Hello, I have a big problem trying to load a scenario, this scenario will be a bowling place, my problem is, when I load the scenario (from a obj file) and try to put a sphere (DynamicPhysicsNode) over it dosen

I dont use jME2 so I dont know much but i think its:

  BoundingVolume BV = new OrientedBoundingBox();

        BV.computeFromTris(indices, TM, 0, TM.getTriangleCount());

You are creating a OrientedBoundingBox - what you want is a mesh based collision shape of some sort.