XS_HIDDEN_REMOVE_DOUBLE_LINES
Category in Advanced options dialog: Drawing properties
To have Tekla Structures draw double lines
when displaying models with Exact representation and creating
drawings and 2D DWG/DXF files, set this advanced option to FALSE.
Note that on the screen, it is very difficult to notice the difference, but if you open the exported DWG file in a DWG editor, such as AutoCAD, you will more easily notice the difference, because you can select one or two lines in the file.
The default value is
TRUE, which means that
Tekla Structures does not draw double lines, to minimize file size.
This advanced option is model specific and the setting is saved in the options database.