When using a Ball Mill, Corner Radius tool, or Taper tools, the tool geometry is honored when the offsets are computed. The full radius offset is applied when the cut depth is larger than the radius of the tool.
In MecSoft CAM, we consider regions to represent edges of walls and you can think of these regions as extrusions to create these walls. The image below illustrates how the ball mill is honored when it meets the edge of a vertical wall. This is referred to as the Waterfall Affect and should be avoided when machining on or around mold parting lines. For this reason ball mills are not recommended for many 2 axis operations such as pocketing and profiling.
The Waterfall Affect