How to Use Orthogonal Mode

Quick answer: Orthogonal mode restricts cursor movement to the X or Y axis of the current coordinate system, so lines snap to 0, 90, 180, or 270 degrees. It’s mutually exclusive with Polar Tracking, turning one on automatically turns the other off, and entity snaps always take priority over it.

What Orthogonal Mode Does

While creating or manipulating entities, the cursor is restricted to moving parallel to the X or Y axis, so lines land on 0, 90, 180, or 270 degrees. As you draw, the rubber-band line follows whichever axis, horizontal or vertical, is currently nearest the cursor.

Toggling It

Any of these:

Click the ORTHO field in the Status Bar.
Press F8.
Hold down Shift (this temporarily reverses whatever the current setting is, rather than toggling it permanently).
Run the toggle command. The page text refers to this as ORTHO, while Octave’s command reference lists it as ORTHOGONAL; both point to the same ORTHOMODE system variable, so either name should work.

Important Interactions and Exceptions

Isometric snap style: if it’s enabled, Orthogonal mode restricts the cursor to orthogonal equivalents within the current isometric plane instead of the flat X/Y axes.
Rotating the axes: the SNAPANG system variable can rotate Orthogonal mode’s axes away from true X/Y if needed.
Entity snaps win: if an entity snap point is available, it overrules Orthogonal mode.
Polar Tracking is mutually exclusive: turning Orthogonal mode on automatically turns Polar Tracking off, and vice versa. You can’t have both active at once.

Frequently Asked Questions

Can I use Orthogonal mode and Polar Tracking at the same time? No. Turning one on automatically turns the other off.

Does Orthogonal mode always restrict me to true horizontal and vertical? By default, yes, but you can rotate its axes using the SNAPANG system variable if you need a different reference angle.

What happens if an entity snap point is available while Orthogonal mode is on? The entity snap wins. Orthogonal mode gets overruled whenever a snap point is available.

How do I temporarily override my current Orthogonal mode setting without turning it off permanently? Hold down Shift. It reverses whatever the setting currently is for as long as you hold it.