This is a powerful command that creates an object by combining shape data from the current selection set. For this command to work, you MUST have two or more shapes in the selection set. Also, these shapes must overlap with each other.

The combined shape that is created is dependent on the way the shape was rendered inside TAD. You see, TAD shapes can either be clockwise or anti-clockwise As far as you are concerned, it does not matter – because visually it does not make any difference.

To know if a shape is clockwise or anti-clockwise; make that object the current object and then press F3 repeatedly. If the red square dot (i.e. the first helper) is going clockwise, then you know that the shape is drawn clockwise!

When you use this command TAD cleverly merges together (in graphic theory it is called a union) all the clockwise drawn shapes. If there are anti-clockwise shapes, then TAD will use that shape to cut out (like a stencil) from the other shapes.

The merge command is very useful to create envelopes