added top level boundin box generation to x3d models

        lv.append((v.X,v.Y,v.Z))

    return lv

def  getBoundBox(freecadObjects):

    """

    Calculate BoundBox for all shapes in the document

    @param freecadObjects - list of FreeCAD objects or all solids/shells

    @return FreeCAD.BoundBox object for the whole document

    """

    shells =[]

    for o in freecadObjects:

        if hasattr(o, "Shape"):

            shape=o.Shape

            for shell in shape.Shells: # solids and open shells

                shells.append(shell)

        elif hasattr(o, "BoundBox"):

            shells.append(o)

    bBox=None

    for shell in shells:

        thisBBox = shell.BoundBox

        if not bBox:

            bBox = FreeCAD.BoundBox(thisBBox.XMin,thisBBox.YMin,thisBBox.ZMin,

                                    thisBBox.XMax,thisBBox.YMax,thisBBox.ZMax)

        else:

            bBox = FreeCAD.BoundBox(min(thisBBox.XMin,bBox.XMin),min(thisBBox.YMin,bBox.YMin),min(thisBBox.ZMin,bBox.ZMin),

                                    max(thisBBox.XMax,bBox.XMax),max(thisBBox.YMax,bBox.YMax),max(thisBBox.ZMax,bBox.ZMax))

    return bBox

def bBoxToX3d(bBox):

    """

    Convert FreeCAD BoundBox to X3D representation (center, size)

    @param bBox - FreeCAD BoundBox object

    @return dictionary of {'center':(xc,yc,zc), size:(xs,ys,zs)}

    """

    return {'center':((bBox.XMax + bBox.XMin)/2,(bBox.YMax + bBox.YMin)/2,(bBox.ZMax + bBox.ZMin)/2),

            'size':  ( bBox.XMax - bBox.XMin,    bBox.YMax - bBox.YMin,    bBox.ZMax - bBox.ZMin)}

    #FreeCAD.BoundBox(0,0,0,0,0,0)

def create_file_info_nogui(shape, fname=""):

    """

    A no-Gui version of the create_file_info, rather useless now as the color

    """

    Collect information about each part/solid to be used for comparison between

    assembly objects and parts

    @param shape - FreeCAD Shape, containing one or more solids

    @param freecadObjects - list of FreeCAD objects

    @param fname - source file path

    @return a pair of a list of info for each solid (as a dictionary) and a

              list of solids in the shape

        info_dict[name] = pickle.load(open(info_path, "rb"))

        progress_bar.next()

    progress_bar.stop()

    FreeCAD.Console.PrintMessage("get_info_files() - loaded");

#    FreeCAD.Console.PrintMessage("get_info_files() - loaded"); #Rare FreeCAD crash?

    #Put largest element of multi-solid parts as the [0] index. 

    for k in info_dict:

            print ("Largest solid is number %d"%(mi))

            if mi>0:

                o.insert(0,o.pop(mi))

    FreeCAD.Console.PrintMessage("get_info_files() - largest made first");

#    FreeCAD.Console.PrintMessage("get_info_files() - largest made first"); # rare FreeCAD crash?

    return info_dict

        materialNode.set('diffuseColor', "%f %f %f" % tuple(diffuseColor[main_color_index * 3: main_color_index * 3 + 3]))

    return shapeNode

def exportX3D(objects, filepath,  id="part", colorPerVertex=False):

def exportX3D(objects, filepath,  partName="", bbox = None, colorPerVertex=False):

    """

    Export given list of objects to a X3D file.

    @param objects - a list of dictionaries in the following format:

            }

    @param filepath - os path of the file to save X3D data

    @param id - id set for the X3D Group node wrapping all the objects in the file

    @param bbox - optional bound box as a dictionary {'center':(xc,yc,zc), size:(xs,ys,zs)}

    @param colorPerVertex - True: specify color per erach vertex, False - for each face (reduces file size)

    """

    progress_bar = Base.ProgressIndicator()

    progress_bar.start("Saving objects to X3D file %s ..."%(filepath), len(objects))

    x3dNode.set('profile', 'Interchange')

    x3dNode.set('version', '3.3')

    sceneNode = et.SubElement(x3dNode, 'Scene')

    groupNode = et.SubElement(sceneNode, 'Group')

    groupNode.set('id', id)

    transformNode =et.SubElement(sceneNode, 'Transform') # Empty transform to adjust center for offset models (use bboxCenter)

    transformNode.set('id', 'transformTop_'+partName)

    transformNode.set('class', 'transformTop_'+partName)

#    if bbox:

#        transformNode.set('translation','%f %f %f'%(-bbox['center'][0],-bbox['center'][1],-bbox['center'][2]))

#    else:    

    transformNode.set('translation','%f %f %f'%(0,0,0))

    transformNode.set('rotation','%f %f %f %f'%(0,0,0,0))

    groupNode = et.SubElement(transformNode, 'Group')

    groupNode.set('id', 'groupTop_'+partName)

    groupNode.set('class', 'groupTop_'+partName)

    if bbox:

        groupNode.set('bboxSize','%f %f %f'%bbox['size'])

        groupNode.set('bboxCenter','%f %f %f'%bbox['center'])

    for o in objects:

        shapeNode = getShapeNode(o["points"], o["faces"], o["color"], o["main_color_index"], colorPerVertex)

    if fname:

        txt += " in "+fname

    progress_bar.start("Generating objects%s to export to X3D ..."%(txt), len(freecadObjects))

    xyzMin=None

    xyzMax=None

    for o in freecadObjects:

        progress_bar.next() # True) # have to do it here as 'for' uses 'continue', True - enable ESC to abort

        if (not o.ViewObject) or (o.ViewObject.Visibility):

            FreeCAD.loadFile(step_file) # os.path.join(ROOT_DIR,step_file))

            doc = FreeCAD.activeDocument()

            doc.Label = partName

            x3d_objects = prepareX3dExport(doc.Objects, step_file) # step_file needed just for progress bar

            exportX3D(x3d_objects, x3dFile, id="part_"+partName, colorPerVertex=colorPerVertex)

            bboxX3d= bBoxToX3d(getBoundBox(doc.Objects))

            exportX3D(x3d_objects, x3dFile, partName = partName, bbox = bboxX3d, colorPerVertex=colorPerVertex)

            FreeCAD.closeDocument(doc.Name)

            FreeCADGui.updateGui()

            numExported += 1

    start_time=time.time()

    info_dict = get_info_files(dir_list) # Will (re-) build info files if missing

    FreeCAD.Console.PrintMessage("generateAssemblyX3d()");

#    FreeCAD.Console.PrintMessage("generateAssemblyX3d()");

    generatePartsX3d(dir_list = [STEP_PARTS], colorPerVertex = COLOR_PER_VERTEX) # Will only run if files are not there yet

    FreeCAD.Console.PrintMessage("generatePartsX3d() Done");

    if not components:

    inlineNode.set('id', ass_with_suffix + '_config')

    inlineNode.set('url',ass_with_suffix + '_config'+ X3D_EXT)

    inlineNode.set('nameSpaceName', ass_with_suffix )

    modelNode = et.SubElement(sceneNode, 'Transform')

    modelNode.set('id','transform_'+ass_with_suffix)

    modelNode.set('translation','%f %f %f'%(0,0,0))

    modelNode.set('rotation','%f %f %f %f'%(0,0,0,0))

    #empty Transform node to move/rotate the whole assembly now translation to -(bounding box center)

    bboxX3d= bBoxToX3d(getBoundBox(components['solids']))

    transformNode = et.SubElement(sceneNode, 'Transform')

    transformNode.set('id','transformTop_'+ass_with_suffix)

    transformNode.set('class','transformTop_'+ass_with_suffix)

#    if bboxX3d:

#        transformNode.set('translation','%f %f %f'%(-bboxX3d['center'][0],-bboxX3d['center'][1],-bboxX3d['center'][2]))

#    else:    

    transformNode.set('translation','%f %f %f'%(0,0,0))

    transformNode.set('rotation','%f %f %f %f'%(0,0,0,0))

    #Group node to provide a bbox center/size of the whole assembly (and center the view)

    modelNode = et.SubElement(transformNode, 'Group')

    modelNode.set('id','groupTop_'+ass_with_suffix)

    modelNode.set('class','groupTop_'+ass_with_suffix)

    if bboxX3d:

        modelNode.set('bboxSize','%f %f %f'%bboxX3d['size'])

        modelNode.set('bboxCenter','%f %f %f'%bboxX3d['center'])

    defined_parts = {} # for each defined part holds index (for ID generation)

    #TODO: Reorder parts - smallest (by a product og gyration radii) first

            part_name = part + ASSEMBLY_SUFFIX

        transformation = transformations[part]    

        bbox=components['solids'][i].BoundBox

        bboxCenter=((bbox.XMax + bbox.XMin)/2,(bbox.YMax + bbox.YMin)/2,(bbox.ZMax + bbox.ZMin)/2)

        bboxSize=  ( bbox.XMax - bbox.XMin,    bbox.YMax - bbox.YMin,    bbox.ZMax - bbox.ZMin)

        bbox= bBoxToX3d(components['solids'][i].BoundBox)

        transform = matrix4ToX3D(transformation)

        rot=transform['rotation']

        groupNode = et.SubElement(transformNode, 'Group')

        groupNode.set('id','group_'+part_name+":"+str(defined_parts[part]))

        groupNode.set('class','group_'+part_name)

        groupNode.set('bboxSize','%f %f %f'%bboxSize)

        groupNode.set('bboxCenter','%f %f %f'%bboxCenter)

        groupNode.set('bboxSize','%f %f %f'%bbox['size'])

        groupNode.set('bboxCenter','%f %f %f'%bbox['center'])

        if defined_parts[part]:

            groupNode.set('USE', part_name)

    def executeMacro(self):

        global COMPONENTS

        COMPONENTS =         None # Start with new ones

        FreeCAD.Console.PrintMessage("Starting conversion...")

#        FreeCAD.Console.PrintMessage("Starting conversion...")

        self.preRun()

        if  self.log_file:

            sys.stdout = open(self.log_file,"w")

reload (x3d_step_assy)

form = x3d_step_assy.X3dStepAssyDialog()

form.show()

x3d_step_assy.generateAssemblyX3d("") #or with path

or just run conversion from the command line in Python console 

x3d_step_assy.generateAssemblyX3d("") #or with path