Rotation after mount mesh to bone

[TomaszFurca]

Hi, after finish inventory GUI in my game - babylon.furcatomasz.pl I have small problem with mesh rotation after mount item to bone. 

For reproduce problem open my game, open inventory and click to any sword to change, then mounted item has wrong rotation.

its my code to mount item:

mesh.attachToBone(bone, meshCharacter);
mesh.position = new BABYLON.Vector3(0, 0, 0);

bone.getRotationToRef(BABYLON.Space.WORLD, meshCharacter, mesh.rotation);
mesh.rotation = mesh.rotation.negate();
mesh.rotation.z = -mesh.rotation.z;

Variable mesh is item to equip.

Thanks for help, Tom.