Edge boundaries gives you three choices on how the toolpaths are generated near surfaces edges.
Does not set any boundary. In this case will only use the boundaries specified on the Boundaries tab.
Sets a pocket-like curve boundary to the silhouette of the part. The tool will contact the surface boundary as shown in the Z-level and parallel toolpaths below. In Powermill this is known as a contact point boundary.
Sets a pocket-like curve boundary to the silhouette of the part offset by a tool radius. The tool will roll over the edges by a tool radius as shown below. In Powermill this is know as a silhouette boundary.
