Aligning the slice plane of the Slice modifier sometimes can be a bit tedious and not so easy.

Especially when you want to align the slice plane, not to world X, Y, and Z axes, but to any arbitrary plane, to the normal of any face, etc.

Using this small script you can quickly align the slice plane to the normal of any plane defined by 3 points.

What you have to do is to run the script and pick 3 points.

If the [ Shift ] key is pressed the slice plane will be aligned to the currently active grid(home grid if no custom active grid is used).

The SNAP will be automatically turned ON when you run the script.