A corridor of interest is used to define the extent of cross sections generated. The corridor of interest is attached to a primary alignment and only one corridor of interest can exist per primary alignment.
There are two types of corridor of interest, freehand and table. Their properties are slightly different, but their purpose is identical.
Freehand corridors of interest are used to quickly select a region that you want to produce cross sections for. They can also be used to create odd shapes to suit required cross section creation. An example might be a "U" shape to create a region either side of a control line without actually including the control line. A freehand corridor of interest cannot be edited; you just create a new one to replace the old one. Also it is not affected by editing its primary control alignment. If the alignment is moved or edited the freehand corridor of interest will remain at the same location.
The table corridor of interest is more formal in its approach. The user enters two offset vales at nominated distances along the alignment. These offset values can be different at each nominated distance, to either widen or reduce the width of the corridor of interest. This builds up a corridor of interest that normally runs parallel along the control alignment. Table corridors of interest can be edited. As they are based on distance along the alignment they will adjust themselves to any changes in the primary alignment if it is moved or modified.
Corridors of interest do not affect cross sections after they have been created. A corridor of interest can be created and a set of cross sections generated within this corridor of interest. The corridor of interest can then be deleted, edited or a new one created so that new cross sections can be generated without deleting the previous cross sections.