请问一个附图说明中的句子翻译问题

The unevennesses 3 of the metal surface are drawn over and shown schematically for purposes of clarity.

请高手指点。

我的理解：
The unevennesses 3 of the metal surface are drawn over and shown schematically for purposes of clarity.

绘示金属表面之不平度3且出于清晰目的以示意图方式来显示。

谢谢 jiekzhang