The AM2DHIDE command creates hidden lines by enabling you to set the objects in front, in the 3D sense, as the foreground , and objects behind as the background .
If you modify the foreground or background objects, or you want to change the object selection for the foreground or background, use the AM2DHIDEDIT command to update the hide situation.
You can include objects in multiple hide situations. For example, an object can be part of the background in one hide situation while it is part of the foreground in another.
When you select objects for the background, the program breaks the objects automatically and moves the concealed areas to the appropriate layer. This function makes the objects hidden lines or invisible. As long as you keep these objects together, you can restore the original representation with the AM2DHIDEDIT command.
You can deactivate the automatic switching off of layers containing concealed elements by setting the system editor key Acad/M > Hide > Invoff to 0. You must switch off hidden or invisible objects before plotting.