Reflection Planes

Aside from reflecting across X, Y, Z axis objects selected from the scene can be reflected across a plane.  One use of reflection planes is to create two parts that are symmetrical on an object.

Setting up a Reflection Plane

Select a surface from scene as Surface A, use Surface: Create Double Sides Surface(s) menu command.  Position double sided surface, example below used Solid: Move A to B Center menu command.  Select double sided surface as Surface B.

Example of Reflection plane used for both halves of an object

 Select object(s) from scene as Solid A, Copy/Paste (assuming objects are being used on both sides of plane) then choose Solid: Reflect Across Surface B menu option.