Rhino Reduce Meshes, the best way


i imported a ASCII format file from IGN Library, so i’ve got a lot of polygones… now i would like to reduce it, but reducemeshe in rhino have 3 options:
polygones count
polygones percent
and plane…
I would like to reduce the number of polygons, without changing the shape by more or less 0.5mm
my file is a reduction of map 2000 x 4000 mm

is it possible?

Hi @onlyforpeace
Take a look at PointDeviation for comparing the original mesh and the reduced mesh - including max and min deviation.
HTH, Jakob