Obb3 constructor

Obb3()

Create a new OBB with erverything set to zero.

Implementation 

Obb3()
    : _center = new Vector3.zero(),
      _halfExtents = new Vector3.zero(),
      _axis0 = new Vector3(1.0, 0.0, 0.0),
      _axis1 = new Vector3(0.0, 1.0, 0.0),
      _axis2 = new Vector3(0.0, 0.0, 1.0);