Polar tracking restricts cursor movement to specified angles. PolarSnap restricts cursor movement to specified increments along a polar angle.
When you create or modify objects, you can use polar tracking to display temporary alignment paths defined by the polar angles you specify. In 3D views, polar tracking additionally provides an alignment path in the up and down directions. In that case, the tooltip displays a +Z or -Z for the angle.
Polar angles are relative to the orientation of the current user coordinate system (UCS) and the setting for the base angle convention in a drawing, which is set in the Drawing Units dialog box.
TM to snap to specified distances along the polar alignment path. For example, in the following illustration you draw a two-unit line from point 1 to point 2, and then draw a two-unit line to point 3 at a 45-degree angle to the line. If you turn on the 45-degree polar angle increment, an alignment path and tooltip are displayed when your cursor crosses the 0 or 45-degree angle. The alignment path and tooltip disappear when you move the cursor away from the angle.
As you move your cursor, alignment paths and tooltips are displayed when you move the cursor near specified polar angles. The default angle measurement is 90 degrees. Use the alignment path and tooltip to draw your object. You can use polar tracking with Intersection and Apparent Intersection object snaps to find where a polar alignment path intersects another object.
Ortho mode and polar tracking cannot be turned on at the same time. Similarly, PolarSnap and grid snap cannot be turned on at the same time.
Specify Polar Angles (Polar Tracking)
You can use polar tracking to track along polar angle increments of 90, 60, 45, 30, 22.5, 18, 15, 10, and 5 degrees, or you can specify different angles. The following illustration shows the alignment paths displayed as you move your cursor 90 degrees with the polar angle increment set to 30 degrees.
The orientation of 0 depends on the angle you set in the Drawing Units dialog box. The direction of snap (clockwise or counterclockwise) depends on the units direction you specify when setting units of measurement.
Specify Polar Distances (PolarSnap)
PolarSnap restricts cursor movement to incremental distances along a polar tracking angle. For example, if you specify a distance of 4 units, the cursor snaps from the first point specified to distances of 0, 4, 8, 12, 16, and so on. As you move your cursor, a tooltip indicates the nearest PolarSnap increment. To restrict point entry to polar distances, both polar tracking and Snap mode (set to PolarSnap) must be on.