Reducing XML file size output

[jborrelli29]

Hello,

I am having a problem when exporting surface data into an .xml format using AutoCAD Civil 3D 2012. I am using LIDAR information to create a surface over an area of approximately 3 hectares in order to undertake future flood modelling. When I have created my surface in Civil 3D the overall file size is around 5MB, however when the surface exported to a .xml format the file is approximately 860MB. I have tried to create a new surface from contour information to decrease overall fle size but with no avail. Does anyone have any reccomendations to decrease the .xml file size without having excessive loss of accuracy for my modelling.

Lidar information that I am using to create surface can be found at https://www.dropbox.com/s/q9kpvfubpa1l3a3/g1m2605933lh.zip?m

Regards,

Joseph

[mathewkol]

XML files are text-based and text-based files are always very much larger than normal compressed DWG files. Same if you were to save to DXF. Unless you make the surface smaller I can't think of how you would make an XML smaller except for one thing...in your settings tab, right click your DWG name and select LandXML options. Look for the surface export option and change some of the options. I'm not in front of a computer so I can't remember the options exactly but I think there is one that exports the minimum amount of data to build the surface.

[rl_jackson]

I believe Matt may be speaking of setting the surface export to point only instead of points and faces.

[mathewkol]

Indeed, that is what I'm speaking of.

[MikeEvansUK]

I'm not sure why you are trying to export the Lidar data as land xml in the first place.

Instead try creating a point cloud of the data then you can import the point cloud into any file and create a surface model in one hit.

The benefit of this is that during the surface creation from the point cloud you can select the density and also apply a boundary to the surface to clip it down to the data area you're working on.

Whilst using the Civil3D surface without the point cloud the working file set may only be 6mb but in the background civil3d will be writing the triangles and point data to another set of files in your temp directory, this was a new feature to enable working with large point files / data sets. When you export the data you are in effect writing the whole data to a landxml file so the file size is expected.

Whilst you could convert and export the points only you already have a points only file in the form of Lidar so I would definitely use point data in this instance.