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Chiara

Importing contours for mesh

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I am trying to open a dxf file of contour lines. I have tried several different dxf files of varying size, the smallest being just under 500MB. SMS will not open these files- is it because they are too large or is there something else I am missing? I have also tried the same contours but in a ESRI Shape format, and SMS gives an error for that too.

Any tips would be appreciated.

Thanks

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John,

Thankyou for your reply. I am using SMS 10.0. Since my last post I have gone back to raw elevation data points, and attempted to import these as an .xyz or a .txt. While this reduces the file size down to about 150MB (compared to contours in .dxf format), SMS gives the error that my computer does not have enough memory to perform the operation (even though the file to import is only 150MB?).

Do you have any suggestions for methods to import large amounts of elevation/contour data into SMS to create the mesh?

Thanks

Chiara

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Chiara,

I am assuming you are trying to import the elevation data to create a scatter set. Although the text file may be only 150 MB, it probably contains millions of points which when triangulated and stored in SMS will take up a significant amount of memory.

On step 2 of the file import wizard, you will see a button that says "Filter Options". You can try using this to reduce the number of points read in.

I was able to read in the following files on my machine (Intel Core 2 Quad CPU Q660 @ 2.40 GHz - 2046 MB RAM) using the filtering options I mentioned. I ran out of memory trying to read them without filtering.

XYZ File 112,399 KB - 4 million points

PTS File 219,861 KB - 7,792,325 points

Remember that a scatter set that is denser than the final grid you use to run your numerical model really doesn't do you any good, since elevation values are interpolated to the grid. I would try to trim the survey data (either in SMS using the filter options or outside in another program) so that it only contains points in the area you will be modeling and reducing the density of the survey data.

Once you have the survey data read in, you may want to consider using the filtering options in SMS to reduce points in planar regions that aren't needed to create a good definition of the underlying bathymetry.

http://xmswiki.com/wiki/index.php5?title=S...ter_(Data_Menu)

http://xmswiki.com/wiki/index.php5?title=S...our_-_Filtering

Probably your best option is to split the .xyz file you are trying to import into several smaller files. Read in the smaller files one at a time, use the filtering options from the data menu ("smarter" options than the ones in the import wizard) and save them out again. Once you have the smaller files filtered, read them in and merge the scatter sets back together.

- John

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