If you want to align the sideline of an element with the sideline of other element, you can use this function.
Take aligning column with beam sideline as an example (under column element currently):
1. Click Align, and then specify the target line that you want to align with, that is, beam sideline.
2. Select the sideline of the column that you want to align. The beam remains unchanged, but the column moves to align with the beam sideline.
3. You can continue aligning with beam sideline.
4. Right-click to select the target line again. To exit from aligning, do not select any line and right-click again.
Take column and beam as examples. When under column element, you can align columns with beam sidelines. To align beams with column sidelines, you can use Align under beam element.