def set_most_driven_shapekey(self,obj):
        ### select most driven shapekey
        index = None
        value = 0.0
        if obj != None and obj.data.shape_keys != None:
            for i,shape in enumerate(obj.data.shape_keys.key_blocks):
                if shape.value > value:
                    index = i
                    value = shape.value
            if index != None:
                obj.active_shape_key_index = index