Polygons > Section by Plane superimposes a plane on the object and:
removes all triangles on one side of the plane (and optionally constructs a plane of polygons into the flat opening), and/or
bisects the triangles on the intersection of the plane such that no triangle crosses the line, thus creating Boundary line. Boundary lines are useful in the Shape phase and in establishing components (“sub-objects”) of a larger object.
Use Ctrl-Z and Ctrl-Y to un-do and re-do any number of actions. This function operates on an entire polygon object or on a selected region of a polygon object.
The controls are:
Align Plane group - allows the specification of a plane that appears superimposed on the object in the Viewing Area. See Methods of Superimposing Planes.
Intersect Plane button - establishes polygons on one side of the plane as “selected” and polygons on the other side an “not selected”. Use this button before Reverse Selection or Delete Selection.
Reverse Selection button - selects all polygons on the side of the plane that is not already selected, and un-selects all polygons that were previously selected.
Delete Selection button - deletes all polygons on the selected side of the plane.
Close Intersection button (applicable after Delete Selection is clicked) - constructs a plane of polygons into the flat opening.
Create Boundary checkbox - specifies that a boundary line is created at the location of the plane when Intersect Plane is clicked. Even if the object is not sliced at that plane (if Delete Selection is not clicked), the Boundary line will remain on that plane.
OK button - saves the object to the Model Manager in its sliced form and/or with any new boundary lines.
Cancel button - closes the dialog without saving any changes to the object.