Regular patches:distance bound NuW-a叭-交，，goro -B.6() Core idea:Measure S(u.)-F(4.)through measuring b,.,-bi. Regular patches: distance bound  Core idea: Measure through measuring S F b1,2 b1,2 3 3 3 3 , , 0 0 ( , ) ( , ) ( ) ( ) ( ) i j i j i j i j u v u v B u B v = = S F b b − = −   3 3 3 3 , , 0 0 i j ( ) ( ) i j i j i j B u B v = =  −   b b S F ( , ) ( , ) u v u v − , , i j b b i j −