Understanding Columns, Grids, AEC Objects, and the ECS
by: Ed Goldberg
URL: http://pointa.autodesk.com/gotoPointA.jsp?dest=15846
 
Have you ever used Autodesk® Architectural Desktop to place a column on a column grid and then on a layout grid? Bet you were mystified at the results. On a column grid columns are placed vertically; on a layout grid columns are placed horizontally. Well don't fret; you're doing it right even if it doesn't look right. Bill Glennie, quality analyst for the Architectural Desktop 3.3 team cleared up the whole matter for me, and hopefully the following tutorial will do the same for you.

Placing a Column Grid
1. Start a new Autodesk Architectural Desktop 3.3 drawing using the Aec arch [imperial] template, and select the Work-FLR layout.

2. Switch to model space by pressing the PAPER button at the bottom of your screen. (If the button reads MODEL, you are already in model space.)

3. Select the SW Isometric View icon to change to the SW Isometric View.

4. Select any empty space near a docked toolbar (but not near the main menu), and right-click to bring up the contextual menu.

5. Select AECARCHX > Grids to bring up the Grids toolbar (see Figure 1).


Figure 1: Select AECARCHX > Grids to bring up the Grids toolbar.
(click image to enlarge)

6. Select the Add Column Grid icon from that toolbar to bring up the Add Column Grid dialog box (see Figure 2).

7. In this dialog box, enter 60'-0" in the X-Width and Y-Depth text boxes. Enter 20'-0" in the X-Baysize and Y-Baysize text boxes. Click the Column button at the bottom of the dialog box to bring up the Add Columns dialog box.

8. Accept the default settings (see Figure 2). Close the dialog box (just click Close), and place the column grid in your drawing (see Figure 3).


Figure 2: At the Add Columns dialog box accept the defaults shown.
(click image to enlarge)


Figure 3: Place the column grid in your drawing.

Note: Placing the column grid using the Column button places the grid and columns at the same time. (If you just want the grid, don't click this button.)

Placing a 2D Layout Grid
1. Select any empty space near a docked toolbar and select AECARCHX > Layout Tools to bring up the Layout Tools toolbar (see Figure 4).


Figure 4: Select AECARCHX > Layout Tools to bring up the Layout Tools toolbar.

2. Select the Add Layout Grid (2D) icon from this toolbar to bring up the Add Layout Grid dialog box.

3. In this dialog box, enter 60'-0" in the X-Width and Y-Depth text boxes. Enter 20'-0" in the X-Baysize and Y-Baysize text boxes.

4. Place this rectangular layout grid in your drawing near the column grid

5. Select Design > Structural Members > Add Column from the main menu to bring up the Add Columns dialog box.

6. In this dialog box select a Standard style column, 12' long, justified at middle center with a roll of 0, and clear the Specify on Screen check box (see Figure 5).


Figure 5: Bring up the Add Columns dialog box.

7. Press the Enter key when prompted to "select grid or RETURN" in the command line.

8. Place a column near, but not on, the layout grid (see Figure 6).


Figure 6: Place a column near, but not on, the layout grid.

9. Select Desktop Anchors > Node Anchor from the main menu.

10. Enter A for Attach object in the command line and press the Enter key.

11. Select the column you placed in Step 8, and then select the closest corner node of the layout grid.

Notice that the column is placed horizontally when it is anchored to the layout grid (see Figure 7.) There is nothing wrong; it all has to do with the ECS.


Figure 7: The column is placed horizontally when it is anchored to the layout grid.

 

What Is the ECS?
Most users know that the UCS stands for User Coordinate System, that ECS stands for Entity Coordinate System, and that every AEC object has an ECS.

To turn on the ECS:

1. Select Desktop > Display Manager from the main menu to bring up the Display Manager.

2. In the Display Manager, expand the Representations by Object tree.

3. Select Anchor Free from the expanded list to bring up its Display Representations.

4. Click the word General; right-click and choose Select All from the contextual menu that appears (see Figure 8).


Figure 8: Choose Select All from the contextual menu.
(click image to enlarge)

5. Click the Apply button, and then click OK to close the Display Manager.

6. Zoom close to the horizontal column that your node anchored to the layout grid.

7. Select the horizontal column, right-click, and select Node Anchor > Release from the contextual menu (see Figure 9). This operation releases the horizontal column from the layout grid.


Figure 9: Select Node Anchor > Release from the contextual menu.
(click image to enlarge)

Notice that both the layout grid and the column have a red, green, and yellow indicator. The red has one arrow, the yellow has two arrows, and the green has three arrows. These indicator arrows define the column's ECS (Entity Coordinate System) (see Figure 10).


Figure 10: The column's ECS (Entity Coordinate System).

In columns, the X direction of the ECS is always along the length.

When anchoring columns to a layout grid, the column ECS always matches the layout grid ECS. This is why the column was placed horizontally when anchored to the layout grid.

When using a column grid with automatically attached columns, the Autodesk Architectural Desktop programmers made the column Normals and Rotation change automatically to make the columns perpendicular to the column grid.

The Reference Object
1. Move the released column away from the layout grid.

2. Select Desktop > Utilities > Reference AEC Objects from the main menu.

3. Enter Ad for Add in the command line and press the Enter key.

4. Select the released column when prompted to "Select an entity to reference" in the command line.

5. Select the bottom of the released column with an Insertion Object snap. A column reference object is created.

6. Move the column reference object to the side of the released column, and accept the default rotation angle of <0.00> by pressing the Enter key. Press the Enter key again to complete the command.

7. Select Desktop > Anchors > Node Anchor from the main menu.

8. Enter A for Attach object in the command line and press the Enter key.

9. Select the column reference object, select a node in the layout grid, and press the Enter key again to close the REFERENCE AEC OBJECT command. The column reference object is now attached to the layout grid node.

10. Zoom close to the column reference object, which is now attached to the layout grid node. Notice the X, Y, and Z direction of the ECS (see Figure 11).


Figure 11: The column reference object's ECS (Entity Coordinate System).

11. Select the column reference object and right-click to bring up its contextual menu.

12. Select Node Anchor > Set Rotation from that menu.

13. Rotate the column around the Y-axis:

  • Accept the X angle rotation of 0,00 in the command line and press the Enter key.
  • Enter -90 for the Y angle rotation and press the Enter key.
  • Accept the Z angle rotation of 0,00 in the command line and press the Enter key to rotate the column reference object.

Copying Columns on Each Node
14. Select Desktop > Anchors > Node Anchor from the main menu.

15. Enter C for COPY to each node in the command line, and press the Enter key.

16. Select the column reference object you placed in Step 9, and then select the layout grid.

17. Enter Y in the command line to skip nodes that already have objects anchored to them, and press the Enter key twice to complete the COPY command.

The column reference object now propagates any changes you make to the original column to all the other columns in the drawing.

18. Select the original horizontal column and right-click to bring up its contextual menu.

19. Select Member Properties from that menu to bring up the Structural Member Properties dialog box.

20. On the Dimensions tab change the A- Start Offset to 5'-0" and the C-Length to 20-'0", and then select the Trim Planes tab

21. On this tab add a trim plane, offset from the End (in drop down list), and rotate it 45 degrees around the Y-axis. Click and then click OK to complete the command (see Figure 12).


Figure 12: Adjust the column reference object's trim plane.
(click image to enlarge)

By changing the column for which you created the column reference object, all the columns change (see Figure 13).


Figure 13: By changing the column for which you created the column reference object, all the columns change.

Conclusion
When you understand some of the underlying concepts that drove the development of AutoDesk Architectural Desktop 3.3, you'll better utilize the software's capabilities. The REFERENCE AEC OBJECT command gives you significant control of drawing objects. Use it with all AEC objects, and you'll reduce errors and improve your productivity.

Good Luck, Ed Goldberg