How to change zoom direction? 1066 GstarCAD Malaysia April 2, 2016 Tips & Tricks 4197 Another related system variable is ZOOMWHEEL which can toggles the direction of transparent zoom operations when you scroll the middle mouse wheel. 0 :Moves wheel forward zooms in; moving wheel backwards zooms out 1 : Move wheel forward zooms out; moving wheel backwards zooms in. Message with a green flag.