User-Defined Point Properties

A local governing authority requires a tree plan submitted with any subdivision application. This tree plan is an inventory of the trees 8 in diameter or larger and a tally of which trees will be removed during construction. In the past, I would have recommended to my clients to simply put together a point table with the tree points shot in the initial survey and leave a blank column to insert some AutoCAD text indicating whether or not the tree would be removed. The following is an example.



I always felt this was the simplest way to handle to problem. It worked fine but if the viewport scale in which this table was shown was different than the annotation scale set in model space, all the text would appear to be displaced. It was clear I needed a new solution, one that would be foolproof and automatic.

I had recently been experimenting with User-Defined Properties (UDP) for point data in which I could add a measure-down for existing manhole survey data and label a point with the rim elevation and the invert (rim elevation minus the measure-down). It seemed to me that a UDP could be defined for this tree status as a String and added to the point data. Here is the procedure I came up with.

Step 1: Define the Property.

From the Settings tab on the Toolspace, right click on the User Defined Property Classification and select New then simply name the classification Tree Data.



Then, right-click on your new classification and again, select New. This will define the UDP. Call the UDP Tree_Status, choose String for type, and make sure the option for a default value is checked on and type in KEEP.



Step 2: Create a Point File Format.

Next, we need to set up a Point File Format (PFF) to accept the soon-to-be-updated point data with six fields of data. We will augment the usual PNEZD five-field format with a sixth field to include the Tree_Status. Simply right-click on the PNEZD (Comma Delimited) PFF and choose Copy.



Rename the new PFF something descriptive and add the sixth field by choosing Tree_Status.



Step 3: Make the Points Available for Update.

In this example, we will assume the existing conditions base map has already been created and all the points exist in the drawing. In order to add the extra field of data to the tree points, we must first export them to a TXT file which will be easy to update. This is an even easier process if the tree points are saved in their own Point Group. Choose the Import/Export Points option from the Points pull-down menu and choose Export.



On the next dialog box, choose PNEZD (Comma Delimited) for the PFF, name and place the file, and limit the export operation to the Tree Point Group.



Step 4: Update the Point File.

Next use a text editor like Notepad to open the TXT file. On the tree points slated for removal, add the text ,REMOVE and save the file. Remember to insert the comma between the description and the tree_status fields.



Keep in mind that adding a field for the trees slated to remain is unnecessary as the default value set for the UDP was KEEP. This will be added to all the incoming points missing that sixth field.

Step 5: Update the Drawing Points.

Next, use the Import Points option to bring in this updated data, choosing the PFF created earlier to accept point data with six fields.



The option to Overwrite data will need to be checked at the warning screen.



You can check your handiwork by looking at the Point List on the Tree Point Group.



Step 6: Create the Table.

Finally, we will need to create a point table style to show off our new data. Copy an existing table style and manipulate the columns to show only point number, raw description, and tree_status.



Produce the table! It is dynamic and will update itself if you manually change the tree_status for any of the tree points.

This page last edited on Thursday, June 03, 2010