To change the Angle Snap setting, right-click the Angle Snap Toggle button on the main toolbar and in the Options panel
General group, edit the Angle setting.
Polar is particularly useful for drawing plans where angles between all lines must conform to specific angle increments, such as 45 degrees. If all lines must be at 90-degree angles to each other, use the Ortho Snapping Mode toggle instead.
The following provisions apply to using Polar:
Polar mode displays a compass that provides a readout of the current angle of the input relative to the positive direction of the local X axis.
in Polar mode, the next point becomes doubly constrained by both the previous point and the first point of the current object. This allows you to close splines precisely. In this mode, two compasses are displayed; one each at the first and previous points. To add Polar Snapping Mode to the Snaps toolbar:
Customize User Interface. This opens the Customize User Interface dialog.
3ds Max automatically saves the toolbar in its revised state and makes the new button a permanent part of the user interface.
To use Polar:
An orange compass appears where you place the first point, along with a red number indicating the angle of the current line segment with the positive direction of the local X axis.
The line jumps to specific angle increments from the X-axis, while the compass reading updates to show the current angle. You set the angle increment in the Grid And Snap Settings dialog
Options panel
General group, which you can access by right-clicking the Angle Snap Toggle button on the main toolbar.
to constrain the mouse by both the previous point and the first point, and then click. This vertex is automatically placed at the current angle increment from the first point, so that you need only click the first point to close the shape.