Landscape size problems

[spittle]

You could try using the retopology tools (Max 2010 & higher) to knock up a new lower res surface based on your current geometry. When you're modelling your new mesh it will snap to your current mesh. The tools are pretty easy to use, you can look in the help files. You can make a nice tidy new mesh and can subdivide it too if you need it to be smooth.

[todes]

thanks a lot i fixed the problem using an autocad extension (quickserve) i will try you're option to see if it gives a better result