To add columns with sections that vary along the column height to a pier, use the following procedure.

1. On the Column Type drop-down list, select Variable. The Column attributes update.
2. In the Column parameters, click […] in the Variation field (following the Variable Sections description). The Variable Column Form dialog opens.
3. (Optional) To add a new section to the table, click Add Section. Each row of the table represents a segment along the columns length. It describes how the selected cross-section varies between the two ends.

   The segments in the table are ordered from top-to-bottom of the column. Use the Up and Down buttons to move the current row up or down in the column height.

   A new row is added to the table.
4. Define the variation of a column segment:
   1. Type the Section Height which is the length of a particular segment.
   2. Select the Shape from the drop-down list in the cell. The same shape is used through the segment, with varying dimensions.
   3. Type the Start Dimensions of the shape at the start of the column segment. This is a comma-separated list of dimensions. The number of required dimensions varies depending on the selected section type.
   4. Type the End Dimensions of the shape at the end of the column segment.
   Tip: Click Update Drawing after you make changes to update the rendering in the Edit Pier dialog.
5. (Optional) To select a user-defined template:
   1. Select Template from the Shape drop-down list.
   2. Edit the Template Details section, and select the column cross section template name.
   3. If the template selected has variable constraints specified, you can define the variation for the selected variables along the length of the column section. The layout of this dialog is similar to the deck variable constraint definition.
6. If you have more than one variable segment, select one as the Adjustable Height segment. This indicates to the program that when the height of a pier is to be updated based on terrain, cross-slope, etc., then this segment will increase or decrease in length accordingly.
7. (Optional) Click Update Drawing to update the 3D view in the Edit Pier dialog.
8. Click OK.