Comparison of two methods for multiresolution terrain modelling in GIS

Abstract

Very important points (VIPs) and important points and edges (IPEs) methods have been compared in accordance with the TINs obtained by: (1) Delaunay triangulation using DEM points determined by VIP and (2) constrained Delaunay triangulation using DEM points and triangle edges determined by IPE. It was ensured that the number of points in each TIN was approximately equal to the number calculated by Topfer's formula, and that the vertical error of each TIN was less than the error calculated by Koppe's formula. According to the results, (1) both methods are quality prioritized, (2) IPE is more sensitive to local surface changes, (3) important triangle edges determined by IPE make a significant contribution to the TIN, (4) some of the points selected by IPE are more important points than that of VIP, and (5) IPE-based TINs are more structural fidelity than VIP-based TINs.