Abstract: The error metric determines the number of triangles per frame, and affects the
fidelity of terrain and efficiency of the algorithm in real-time rendering in dynamic terrain
visualization. The screen error calculation method requires a lot of maintenance work and
produces a large number of redundant triangles to eliminate T-junction and crack in the real-time
rendering. So this will reduce the speed of real-time rendering of terrain. In this paper, the local
roughness factor constraint nested sphere of error metric is used to provide a better reflection of
the details of local topography and reduce redundancy triangles in flat region. Computation
complexity in real-time rendering can be reduced by using the delay estimate frame coherence and
thus the efficiency of the algorithm can be further improved. Experiments demonstrate that the
dynamic terrain visualization algorithm, by using the error metric with constraints, can effectively
reduce the redundant triangles and can represent the deformed region very well in real-time
rendering with improved efficiency.

Key words: LOD, dynamic terrain, roughness, nested sphere of error metric