The use of variable allows the operation's register to be global, that is, using variables instead of fixed values makes it possible to apply the same patterns to pieces with different dimensions.
What are the variables that can be used? The variables accepted are:
$DX$ or $dx$ = corresponds to the width of the piece
$DY$ or $dy$ = corresponds to the depth of the piece
$DZ$ or $dz$ = corresponds to the height (thickness) of the piece
The variables can be found next to the dimensions of the piece, in the upper left corner of Plugin Editor:
How to use variables?
To illustrate the use of variable, observe the drillings registration on a base with the following dimensions:
Width (DX): 524.8 mm
Depth (DY): 550 mm
Thickness (DZ): 15.6 mm
Notice how the drilling was registered:
When using $dz$/2 in X the drilling will always be positioned exactly in the middle of the panel thickness, regardless of the thickness value.
When using $dy$/2 in Y the drilling will be positioned right in the middle of the depth of the piece, regardless of the depth value.