Mass points
Mass points are the nodes from which
triangles are constructed; they determine the TIN
structure. Mass points can be the features in a point layer or the vertices in
a line or polygon layer. They must have elevation values.
Mass points can be spaced
regularly or irregularly. The TIN
surface will be more accurate if surface extremes and discontinuities (peaks,
valleys, tops and bottoms of cliffs) are plentifully represented by points.