Main toolbar > Align to View (on Align flyout) > Align to View dialog
The Align to View dialog lets you align the local axis of an object or sub-object selection with the current viewport.
You can use Align to View with any selection that can be transformed.
Procedure
To align the local axis of a selection with the current viewport:
Select the objects or sub-objects to align.
Click Align to View.
Specify the local axis of the selected object to align with the current viewport's Z-axis.
Select the Flip check box when you switch the direction of the alignment.
The alignment takes place while the dialog is displayed.
Click OK to complete the process.
Interface
The Align to View dialog contains the following options:
Align X, Align Y, Align Z: Specifies which local axis of the selected object will be aligned with the current viewport's Z axis.
Flip: Switches the direction of the alignment.