The perimeter of the TIN resulting from the triangulation process corresponds to or approximates the convex hull of the TIN vertices. This may result in some long thin triangles or "slivers" on the perimeter of the triangulated region. There are several ways to deal with the long thin triangles.
Thin triangles can be selected and deleted using the normal selection procedures. There is also an option for selecting thin triangles when the Select Triangles tool is selected. If the Control key is held down, it is possible to drag a line with the mouse. All triangles intersecting the line are selected.
Long thin triangles on the perimeter of the TIN can also be selected by selecting the Select Boundary Triangles command from the TINs menu. The Select Boundary Triangles command checks triangles on the outer boundary first. If the length ratio of the triangle is less than the critical length ratio, the triangle is selected and the triangles adjacent to the triangle are then checked. The process continues inward until none of the adjacent triangles violate the minimum length ratio.
The critical length ratio for selecting thin triangles can be set by selecting the TINs | TIN Settings menu command. The length ratio is defined as the longest side of the triangle divided by the sum of the two shorter sides.
Related Links:
Editing TINs