This TechNote explains the steps necessary to create a TIN (Triangulated Irregular Network) and profile with GeoTerrain by GEOPAK.
Creating a TIN
1. Create a design file of x, y, z points with the XYZtext import tool (choose Tools > Annotation > XYZtext).
2. Extract a DAT file from design file data (choose Extract > Graphics).
In the above example, everything will be extracted from the design file because no selection criteria were specified. If the design file contains many graphic elements, these criteria are used to create a "selection set" of the data. For example, if the design file contained contours that were to be used to create the TIN as well as roads, buildings and waterways, the contours could be extracted from the file using any combination of the selection criteria.
3. The next step in the process is to Build Triangles. We will use the input DAT file to create a TIN surface (choose Build > Triangles).
After selecting the DAT input file and a location for the output TIN file, click the process button to create the TIN.
4. The final step is to load the DTM Feature, which in this case is the TIN file we created in Step 3 (choose Load > DTM Feature).
Turn on the Display Only button until you are satisfied with the color selections for each feature. Click once on each Feature to select it and adjust the settings that appear at the bottom of the dialog. The check mark to the right of the Level, Color, Weight and Style settings indicates whether the feature is set to Display (ON) or not (OFF). Only the features selected for display will be added to the file. The light bulb buttons to the right of the features control the Display status of the features. The top 2 buttons Select All on or off. The bottom 2 buttons control the on/off status of individual features.
Generating a Profile
1. Select the TIN file and add the profile type by clicking on the Add list item (top button on the right hand side of the dialog). The TIN file will be added to the list as shown below.
2. Next click the Profile Tab. This is where you pick a graphic element that represents the cross section, or draw the cross section on the top view of the surface. The profile is dynamically updated in the profile screen.
3. Next click the Preferences Tab. This is where the settings for the cross section grid, text, intervals are set. These can be adjusted and the results checked dynamically by clicking the Profile Tab.
4. The final step is to return to the Profile Tab and click on the Place Profile button. Click in the view window in the location that the profile is to be placed in the design file.