In 1995 InSite SiteWork became the first earthwork take-off software to use Constrained Delaunay Triangulation to generate the existing, proposed, and underground strata surfaces. In plain English, it is simply the most accurate method available for surface generation, and gives the most accurate site representation and therefore the most accurate site work quantities.
Triangulation is now used by major design software such as Autodesk Civil 3D, Bentley Microstation, Eagle Point, etc. and all machine control systems from such as those from Leica, Topcon, Trimble and Hemisphere.
There is a video on the web from a gentleman who may be quite sincere but is sadly misinformed. The statement is that triangulation can only calculate data at triangle vertexes and therefore the triangulation is an approximation. In fact, in InSite SiteWork there is a triangle vertex at EVERY actual data point and since triangles are 3D planes we can calculate EXACT elevation values for EVERY point on the surface.
The reason Delaunay triangulation has become the gold standard for surfaces is that it is mathematically the most accurate representation of a surface that can be obtained from the available data. This is the reason that in 1995 InSite Software upgraded from the grid method which only gives an approximate result.
One other benefit of triangulation is the high quality 3-D representation available from the TIN model. There is never a question of how InSite SiteWork or Field General is calculating elevations as the TIN model is presented in both the 2D plan view and the 3-D model of the site. Since earthwork take-off often requires presentation to validate the accuracy of the take-off, a presentation based on triangulation will be exact, unlike the murky 3D’s generated by other methods.
At InSite Software, we have specifically optimized InSite SiteWork for accuracy, ease of use and ease of verification.