__init__.py

def _AiNode(node, prefix, nodes, mat):
    """
    Args:
        node (ArnoldNode): node.
        prefix (str): node name prefix.
        nodes (dict): created nodes {Node: AiNode}.
    Returns:
        arnold.AiNode or None
    """
    if not isinstance(node, ArnoldNode):
        return None

    anode = nodes.get(node)
    if anode is None:
        anode = arnold.AiNode(node.ai_name)
        name = "%s&N%d::%s" % (prefix, len(nodes), _RN.sub("_", node.name))
        arnold.AiNodeSetStr(anode, "name", name)
        nodes[node] = anode
        for n in mat.node_tree.links:
            # if input.is_linked:
            _anode = _AiNode(n.from_node, prefix, nodes, mat)
            if _anode is not None:
                arnold.AiNodeLink(_anode, n.from_socket.name, anode)
                continue
            if not n.hide_value:
                _AiNodeSet[n.bl_idname](anode, n.from_socket.name, n.default_value)
        for p_name, (p_type, p_value) in node.ai_properties.items():
            _AiNodeSet[p_type](anode, p_name, p_value)
    return anode