Polygons > Primitives is a set of functions that a) create plane and cylinder objects based on the geometry of a polygon object, and b) force a selected set of polygons into a planar or cylindrical shape.
Polygons > Primitives > Fit to Plane - moves a selected set of polygons until they strike a user-specified plane, and stretches one band of surrounding triangles to form a wall along the projection path.
Polygons > Primitives > Fit to Cylinder - calculates a cylinder that best fits the selected triangles and projects all selected triangles to that cylinder.
Polygons > Primitives > Project Region - moves a selected set of polygons until they strike an existing Plane or Cylinder object, and stretches one band of surrounding triangles to form a wall along the projection path.
Polygons > Primitives > Create Plane - creates a Plane object that fits the selected polygons.
Polygons > Primitives > Create Cylinder - creates a closed-end cylinder that fits the selected polygons.