There are two mainly error rules for the generation of multi-resolution model of terrain

one is screen space error

the other is terrain roughness

however

both of them are liable to reduce the area near or not very far from the viewer

because they discard 2 of 3 dimensions of a vertex. In this paper

first

a rule named remaining energy is proposed which is suitable for reducing the area far or very far from the viewer

the principium of the rule is that the light eradiated from surface will attenuate during its transmission

so the light energy eradiate from the surfaces far from the viewer will become too faintness to attract the viewer's attention

thus the surfaces far from the viewer can be emerged into larger surface

then the rule based on vision principle is formed by combining remaining energy rule and terrain roughness

in the end

an algorithm and its implementation based on quadtree for generating terrain multi-resolution model under the vision-dependent rule is described in detail

the algorithm can simplify the terrain effectively and is proven to be very valid for the reduction of large scale terrain at the same time.