Chapter 17 | Creating Terrains from Survey Data

TOTAL STATION SURFACE BUILDER

Virtual Tutor: Go to help > point array > triangulate to learn more about creating surfaces from total station data.

In Chapter 16, we reviewed how to import your non-point cloud survey data into your project. Once your points are imported, you can create a connected triangular mesh to be used as a terrain mesh object simply by going to the “triangulate” menu in the left side control panel, and enabling “triangulate” (see below). Note, in this example, “receive projection” is enabled, which texture maps the surface using the Google Earth image below. “add corners” is also enabled to create a completely filled rectangular surface by placing surface points at ground level far from the original point array set. This is useful for point sets which are sparse which can result in gaps in the resulting mesh. 

Note in the example above, point 3 should not have been used in the surface building process, as that point is from shooting a light pole high in z. This point can be separated into a new point array object simply by left-clicking the point name in the point list, then pressing the “detach” button (see below). Multiple points can be selected at once and all moved into a new point array in the same manner (Virtual Tutor: Go to help > point array > detach).

With point 3 detached, the surface building process correctly excludes that point.

Point arrays can be merged by pressing the “attach” button in the “points” menu. Then left-click on the point array you would like to merge with (Virtual Tutor: Go to help > point array > attach).


As with any 3D object, the point array can then be made into a terrain surface by left-clicking on Physics > Make Unyielding / Terrain From Selection. 

The point array can also be made into a mesh object by left-clicking on “to mesh” in the “tools” menu. Once this option is used, the point array will lose its special point list functions, and the point array will be converted into a simple mesh. This can be useful to modify properties of the surface polygon faces for example. 
 

You can force a new polygon edge to be created between two points within a point array simply by pressing the “connect” button in the “points” menu, left-clicking on the first point and left-clicking on the second point (Virtual Tutor: Go to help > point array > triangulate). 

Once the second point is selected, you will see a new edge created (see below). You can continue left-clicking on other points to connect them, or right-click to terminate the connect feature.  

You can also force your total station surface to intersect with variable height contour polyline paths and shapes to help build complex surfaces. The polylines can either be set to have uniform height, or you can specify the height along the polyline path. In the example below, a simple line segment is drawn. The feature is enabled by simply left-clicking on “pick node” then left-clicking on the line object. The surface mesh is then forced to intersect with the polyline whose height is fixed to 7.229 feet (Virtual Tutor: Go to help > point array > paths).

You can see an example simulation using this environment below. 

Tags: Importing data, measurements, total station, RTK GPS, measurement log.

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