TINMaker is a shareware landscape application used to build a TIN model. It is possible to work with TINs in several ways. For the landscape designer, TINMaker provides a simple way to generate a view of a surface for the site you are working on. The surface can be viewed, and detailed information about the flow of water, and contours can be generated. Most importantly for gCADPlus users, the TINMaker data can be imported to a gCADPlus landscape design file.
More on TINs
TINs are used in survey and GIS work to represent surface topography. The abbreviation TIN stands for Triangulated Irregular Network. Much useful information can be derived from a TIN – contours can be interpolated, sections cut, surface cut, fill volumes calculated, etc. If you would like to download a free copy of TINMaker, click the link below.
View an example of a TIN surface loaded into our companion landscape design software gCADPlus.
Want to know more about TINs?
Here is a link to a Wikipedia article on TINs.
Briefly, the steps are:
- Obtain some surface point data
- Make sure that the data is in the form of a simple text (ASCII) file
- Import the datafile into TINMaker and check for duplicates
- Create a boundary for the collection of points.
- Create the TIN surface
- Set view options
- Export the TIN
- Import to gCADPlus.
Here is a (rather long) movie showing the steps in a typical TINMaker project. Extract three-dimensional information from polylines in a CAD file provided by a survey firm. Using a combination of tools we study surface topography in gCADPlus landscape software.
The Points drop menu allows the importation of point data.
The figure below shows some typical input survey data of the type used by TINMaker.
Note that data from automated digital survey equipment is often passed to survey software such as Liscad and point data is exported in the form of a comma-separated ASCII text file. In this example, each record in the file contains just 3 items – a code with the X, Y, and Z values.
Tip: These input data files must have the .txt extension. A fourth data column containing a unique point number for each record needs to be created. Excel is a suitable tool for that step.
Create a boundary
The tools drop menu is used to create a boundary. We find the Auto Boundary tool works well.
The yellow line in the figure below is the boundary enclosing all the points in the data file.
Perform triangulation to create the TIN
Once the boundary is set, the Triangles drop menu is activated and the command triangulate is activated.
View the resultant TIN
The image below shows a typical TIN made by importing the data above to create a series of independent blue triangles covering a site. The dark grey channel running from the top left to the bottom right of the image represents a watercourse while the green lines represent contours. A road bridge spans the watercourse.
The triangles, shading, and contour lines are generated from ASCII files containing X, Y, and Z point values. These point data values are often obtained directly from digital survey equipment and imported into the software. Once loaded and the TIN generated, extra data such as point code or z value can be displayed on the model below.
The green lines represent contours and in later versions of the software, it will be possible to export isolines as DXF files with the elevation of the polyline corresponding to the contour interval.
The TINMaker interface shows six drop-down menus. File, View, Points, Triangles, Tools, and Help.
The upper portion of the File menu enables existing TIN files to be loaded or previously edited TIN files to be saved.
Tip: TINMaker has facilities for removing triangles, adding new point data, moving points, etc.
A list of TIN files recently worked on is also available.
Part of a TIN file can be saved by locating a boundary around a subset of points.
The lower part of the File menu provides tools to load X, Y, and Z point data files.
X, Y, and Z data can also be exported using an option on the menu.
Import point data examples
Several sample point data files are available for testing TINMaker. You will find these in the TINMaker installation folder
Tip: If you work with relatively few data points they may be difficult to see. Use the wheel of the mouse to zoom in and the points will show up.
The tools on the View drop-down menu are used to control point visibility. Note that items such as Triangles (for the TIN), Isolines (contours) are ticked (active), but as no boundary has yet been established, no TIN data is visible.
For that to happen, we need to move to the Tools drop-down menu and choose AutoBoundary. This tool is used to create a boundary within which triangulation will occur.
If the automated boundary option is chosen, the software searches for the outmost points and creates a boundary delineated by the yellow line as shown in the figure below. The software provides the user with a dialog box to control the search criteria.
Once the boundary has been established, it is time to switch to the Triangulation drop-down menu and generate the actual TIN surface. The figure below shows the result of selecting Triangulate.
Now the options selected as active on the View drop-down menu come into play. The TIN surface shows a set of blue triangles, and contours (isolines) are shown in green. Here is another example.
Note that this menu provides tools for editing TIN elements.
Tools for manipulating points are located here. Adding extra points from a different (perhaps later) survey is possible. Points can be deleted, or subsets of point data defined inside a new boundary can be exported, and so on.
The figure below shows a view of this model with the triangles off, but filled – the triangle option in the View drop-down menu is turned off to show a rather nice view of the ground topography.
Note that at this stage of development of the software, it is not possible to view the terrain model as a 3D object.
Not every text file can be read by the software; it needs to be correctly formatted. The figure below shows an example of a CSV file that cannot be read by TIN Maker. This data came from a depth sounder and GPS device during an underwater survey. The data was presented without a text code.
Import TIN to gCADPlus
Use the link on the File drop menu.