Both contours and breaklines are representations of the shape of a piece of ground. A contour represents a slice of the terrain at a specific elevation. Contours allow the viewer to see changes in elevation at a glance, but provide only a rough digital model of the surface. Breaklines, when done correctly, provide specific detail beyond the contours, adding facets to the terrain model. Contours can be very accurately created from breaklines, but not vice versa. Breaklines exist everywhere there is a crease in the grade. When the slope of a spot on the ground differs from the slope of an adjacent spot, that is a break in the grade and defines a ridge or crease in the surface. Those creases and ridges are where we create breaklines. And most often, they are not visible to the human eye unless seen from just the right angle with just the right lighting. Our proprietary software finds breaklines that would be missed otherwise.
The traditional DTM definition, is a terrain model composed of many different types of digital surveyed data, including breaklines, points, contours, and boundaries. Autodesk has included newer complex object types such as grading objects, COGO points, recap files, DEM’s, Feature Lines, meshes and more. Datasight creates the DTM basics: polylines and points. This makes it completely compatible with any DTM creation program, whether it’s from Autodesk, Bentley, ESRI, or any other terrain modeler. DTM’s that are made solely from breaklines and points are an accurate and efficient way to define detailed terrain models with the smallest possible dataset.