不规则曲面杆件做法，最后一步利用编码工具C# script 将网格曲面挤出厚度,编码按照课程设置，但电池块变红，显示以下错误：
1. Error (CS1061): 'Rhino.Geometry.Mesh' does not contain a definition for 'offset' and no extension method 'offset' accepting a first argument of type 'Rhino.Geometry.Mesh' could be found (are you missing a using directive or an assembly reference?) (line 70)
