If you draw your scissors shape on a slice view instead of on the 3D view you can limit its extent. See the Slice Cut options. Also, you can use the Circle shape option.
You might find the discussion here helpful.
If you draw your scissors shape on a slice view instead of on the 3D view you can limit its extent. See the Slice Cut options. Also, you can use the Circle shape option.
You might find the discussion here helpful.