Not only the DTM creation with a reliable delaunay triangulation algorithm but this program it's prepared for civil engineers and surveyors because it has the possibility to include break-lines and to draw the contour lines without smoothing or with a reliable smoothing algorithm and too, you can add labels on the contour lines.

The program runs in Autocad 2007/2008/2009, Autocad 2010 and BricsCAD v10.

There is not any professional program on internet like this and you can get it without any effort. I think this could be a handicap because it's dificult to believe, but it's true; try it and you'll be surprised.

It's not only a program to calculate a delaunay triangulation but you can input break-lines to get a real representation of the terrain.

The first version of this program came onto the market in 1992 and there are more of 3000 professionals working with it, civil engineers, architects, foreman builders, surveyors, mathematics, etc.

I tried the program with 1000000 of points and It had not problems to calculate it. The program is more slow when you have too many break-lines, (more of 20000).

You can open until five instances of the program and work with a different DTM in each. Only, write "LanDTM" on the command line and you'll see other 'LanDTM' window.

You can calculate the volume between two DTMs. There are two ways to get it.

The first, and more easy, is to make a "grid" for each DTM and to calculate the volume for the sum of each paraleliped formed. This is done with a single order, "Tools/Make 3D grid", where you can select between to calculate a single grid of points or a grid of points which elevation is the difference between two DTMs. After you can use "Tools/Grid Volume" to get the volume in cubic meters.

The second, and more accurate, is to calculate the volume between two triangulations projecting each of it in the other and calculating a new triangulation as result. It's a litle more complicated to explain but the calculated volume is the exact. This option is in the "Applications/DTMs intersection" in the main menu of the "graphic dialog box".

After to make the DTMs intersection you can use "Applications/Model volume" in the main menu to get, in cubic meters, the total volume between them.

Main features

*The price.- There is not any professional program on internet like this and you can get it without any effort. I think this could be a handicap because it's dificult to believe, but it's true; try it and you'll be surprised.
*Professional.- It's not only a program to calculate a delaunay triangulation but you can input break-lines to get a real representation of the terrain.
*History.-The first version of this program came onto the market in 1992 and there are more of 3000 professionals working with it, civil engineers, architects, foreman builders, surveyors, mathematics, etc.
*Quick, no points limit and reliable.- I tried the program with 1000000 of points and It had'nt problems to calculate it. The program is more slow when you have too many break-lines, (more of 20000).
* Flexibility.-Usually, the programs are hard when it's necesary to edit the calculated triangulation and they have yours owners tools to do it. This is good because you see the modifications in real time and LanDTM has these tools, 'insert line', 'change edge', 'insert point', 'delete triangle', etc, which they are in a Tool Bar easy to handle. The contouring and triangulation are drawn again as you edit with these tools.

But, that's not all, given the best feature of LanDTM is that you can exit the program and to edit the triangulation lines like you want with all the power of the CAD edit tools, deleting, inserting, "intersecting", changing elevations, triming, extending, etc. If you are in a CAD you must to take advantaje of it. When you finish the edition, simply you import the modified lines, and the program will not have problems to create, again, the new triangulation.

* Safety.-A good program to make DTMs must to have a system to find errors. The most tipical error is that you have a line with elevation 0.0 or a line don't have a support point. When you edit the triangulation by hand it's very common to make errors. So LanDTM program shows graphically the triangles without adjacents, (without neighboring), paint them with other colour for your prompt finding, and the only triangles without adjacents should be the triangles in the external area of the drawing, if you see triangles without adjacents in the center of the working area it means there is an error.

Other way to find errors is drawing the triangulation lines and to change the view point to check if there are "rare" lines. We must take advantaje the CAD power and to use it for our own benefit.
Multitask.-You can open until five instances of the program and work with a different DTM in each. Only, write "LanDTM" on the command line and you'll see other 'LanDTM' window.
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Smoothing test.-A profesional program for civil engineering it's not profesional if It doesn't have a smoothing test. When you make the smoothing of the contour lines, after you must check if the resulting smoothing curves intersect between them and if this is appreciable or not. LanDTM has a tool, to work in background, with which you'll be able to see all the intersections between curves and It'll draw a circle in the intersections points to correct the curves or to decide if to make the smoothing contour lines with differents parameters.

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Volume calculation.-You can calculate the volume between two DTMs. There are two ways to get it.

The first, and more easy, is to make a "grid" for each DTM and to calculate the volume for the sum of each paraleliped formed. This is done with a single order, "Tools/Make 3D grid", where you can select between to calculate a single grid of points or a grid of points which elevation is the difference between two DTMs. After you can use "Tools/Grid Volume" to get the volume in cubic meters.

The second, and more accurate, is to calculate the volume between two triangulations projecting each of it in the other and calculating a new triangulation as result. It's a litle more complicated to explain but the calculated volume is the exact. This option is in the "Applications/DTMs intersection" in the main menu of the "graphic dialog box". After to make the DTMs intersection you can use "Applications/Model volume" in the main menu to get, in cubic meters, the total volume between them.

* Fill and cut.-With the volume calculation you get a grid or triangulation where each point has the difference between the two DTMs, so that you can calculate a new triangulation with this calculated points and you'll get a cloud of points where the negative elevation is the cut and the positive elevation is the fill. You can draw 'SOLIDs' entities to see, by colours, where there are cut and where there are fill. A map very useful in civil engineering.

*Dinamic longitudinal profile on DTM.-Draw a polyline on a DTM in the CAD and with "Applications/Dinamic profile on DTM" option you'll see how a graphic, with a longitudinal profile, goes changing in real time.
*Slopes according a poligon.-Many times you have a project where you must place a plain over the terrain to can make a built, parking, platform, etc, and you must level it. This leveling, you want to make, needs slopes in the limits of the plain. With this tool you'll be able to draw the lines of the resulting slope, of cut or fill.

*Import/Export.- Given the program only allows import/export drawn entities or coordinate files in Protopo "*.CRD" format, you can think the program needs a good way to import/export files, it's for that I've included with LanDTM program other program to import/export files to Protopo CRD files or to DXF files. The program is named ProLink and with it you'll be able to create any ASCII file format you want and to make it compatible with "Protopo CRD files" or "Autocad DXF files".