TRANSFERENCE OF PROPERTIES ACROSS WATERLINES
This image illustrates a stage in the linking a medial-axis with the elements of the TIN converted from a 1:250,000 contour overlay. One of the areas enclosed by adjacentes contours was filled with the waterlines obtained in the first step of the conversion. In addition, every contour segment S in this image was assigned a color representing an attribute. In an actual conversion that attribute is a pointer P to the contour segment S. During waterlining, those Ps are passed from waterline to waterline. Further one, in the medial-axis step, pairs of Ps, one for the S to the left and one for the S to the right, are combined into a code C and assigned to the medial-axis, unrepresented in this page. During triangulation, Cs are split and assigned to the corresponding triangles. The conversion concludes with triangles, contours and medial-axis all reciprocally connected.
For more on this transfer see