This method is a wizard that creates geometry by projecting straight-walled surfaces as in this figure .
The method performs the following steps:
Identify straight vertical surfaces from the selected set or from all surfaces (depending on the option selected.)
Project these surfaces on to the current UCS.
Convert the curves into lines and arcs.
You are then ask to choose from:
Remove after chaining - select this option if you only want chain this geometry once.
Keep all geometry – select this option if you want to make permanent arcs and lines from this process.
You are then put into chaining mode to create curves. See Chain pieces into a closed boundary or Chain pieces into an open boundary for more information on chaining.