Assign Points
Each point in the data file is projected onto the DTM. The Z value of the data point is compared to the Z value of the DTM. The value written to the Code field for that point depends on whether the point is above, below or outside the DTM.
Input
On the Input/Output tab of the DTM Assign form, specify the following parameters:
File
Double-click (or click on the Select icon) to select the name of the Input file. The default file type for Point data is DAT. If necessary, you can apply a filter to restrict the process to a subset of the data in the file.
X, Y and Z fields
Specify the names of the fields in which Easting, Northing, and Z coordinates are stored in the Input file.
DTM
Select a wireframe that defines the Assign Region.
Type
Double-click (or click on the Select icon) to select a wireframe type. The default is DTM.
Name
Double-click (or click on the List icon) to select the name of the wireframe (of the type you have selected).
Side of DTM
If the wireframe is a solid rather than a surface, the Side of DTM prompt allows you to specify whether a TOP or BOTTOM value is to be used when comparing values with Z values in the data file.
Output
You can choose to Overwrite the input file or nominate an Output file as the target file to which assigned values will be written.
If you are overwriting the Input file, records that do not pass the filter are only removed from the file when one or more of the Delete Data options are selected on the Points tab of the form.
Overwrite input file
Select this option to write the assigned values back to the Input file.
File
If you do not want to overwrite the Input file, select a file type and enter (or click on the Select icon to select) the name of the Output file.
Delete Data
Optionally, choose to delete data which is above, below, or outside the DTM.
Forms
Click the Forms button to select and open a saved form set, or if a form set has been loaded, save the current form set.
Run
When you have specified input and output parameters and setup the values to assign to the attributes of the DTM, click Run to begin the Assign process.