contours

[sturner]

i have the fun pleasure of dealing with terramodel and LDD2004. recently i have been using land XML to import the dtm from terramodel and point file with descriptor keys. now everything works fine the question arises when you overlay the terramodel contours and LDD contours. they do not line up close but no cigar, so the bosses and i question the accuracy. it also need the breaklines to be built into the surface for the contours to pull correct. is this a common thing that i will have to live with? please advise.
thanks!

[MHultgren]

Sturner,

With the differences between TerrorMudel and LDT you will probably NEVER get the exact same surface. The methodology of the two is not quite the same and if you had the same criteria it would still be a little different. As far as accuracy, since both packages perform the same function with different approaches, the end result should still be within +/- .5% of the total. Which in Earthworks, is usually well within acceptable limits. You can always make your criteria more stringent, but you will suffer in speed of working with the files. The finer the criteria, the larger the files. On a twenty acre site you can lose .5% of your dirt if you have a rain or windstorm come up. At least out here in the desert anyway!