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CONVERSION of BREAKLINES and MASS POINTS into TINs

For this, the most popular conversion for small area surveys, Civil Engineering projects, etc, we present several pages with results of conversions of real-world data as well as conversions of data devised to highlight particular aspects of our software. This popular conversion of mass points and breaklines into TINs is used so widely that to attain any improvement in the current practices seems hopeless. However, that is not so: in several areas of this conversion it is still possible to notice marked differences in approaches and quality of results.

One of those other areas is the smoothing of TIN-derived contours. Smoothing can be attempted in several ways. As part of our conversion software, we apply a method, the Eclectic Procedure, that guarantees that contours never intersect each other and that spurious undulations are not introduced in the contours. Additionally, our software ensures that contours cross TIN edges on the right side of TIN vertices.

The number and shapes of triangles in a TIN is another aspect of the conversion that deserves examination. If the data only contains mass-points all conversions should yield the same TIN, unless the point set presents singularities (as four points on a straight line) which are circumvented only by well-designed software. The non-singular differences arise from the existence of breaklines and the manner in which they are used to shape the TIN. Important differences may also be seen when breaklines are inserted into an existing TIN.

In third place we must mention another post-processing activity: the clipping of TINs. A very simple process in plane sets when the clipping is executed with square cuts, it becomes more challenging when the data is spatial, as in the case shown on the left. As to our own solution, we must say that we spent considerable time and effort extending its functionality to clipping patterns (cookie cutters) of arbitrary shapes, as well as providing tools to dissolve cuts when edited cookies are inserted back into the TIN.

We are available to answer your questions and to consider any ideas of collaboration with professionals, service bureaus and software developers.