Nick Antonov, a senior GIS draughtsman, discusses using the third mouse button in AutoCAD.

"I double-click the middle button on a three-button mouse to zoom extents. When mice equipped with a scroll wheel came out, I started using the middle button to pan too — just press and hold the middle button and move about your drawing. But one can also customize the middle mouse button's behavior with the variable MButtonPan.

"Also, in 3D model space, you can press Shift and the middle button to execute a 3D orbit. The middle mouse button gives you fast switching between zooming in, zooming out, 3D orbit, pan, and zoom extents — all with one button.

"In some AutoCAD verticals the Shift+third button combination is not assigned to 3D orbit, but instead has a shortcut menu assigned to it. If you would like to use it, you will have to program it through the CUI (Customize User Interface) Editor. In the CUI, go to the Customize tab > Mouse Buttons > Shift+Click > Button 3, and on the right pane replace the macro setting with:

^P'_3DORBITTRANSPARENT ^P

Notes from Cadalyst Tip Reviewer Brian Benton: The mouse is your main way to interact with AutoCAD. It has standard settings out of the box, but you can customize them. In order to use a custom command for the middle button (the scroll wheel), set the system variable MButtonPan to 0 (zero). That will use the macro settings that you can change in the CUI. Otherwise, it will act as the Pan command.