Click this checkbox to create an arc line approximation for toolpaths that are contained in the XY, YZ and XZ planes. This allows 3D programs to be smaller and to result in smoother surface finishes for certain types of parts.
Arc/line approximation applies to the following 3D techniques
X-parallel and Y-parallel roughing or finishing with Parallel Angle set to 0
Z-level finishing
Iso-line finishing where the toolpaths line in a plane
Note that there is no arc/line approximation attribute for Z level rough. Arc/line approximation is always performed on Z-level roughing passes.