Import DEM (ASC) Files

[Anonymous]

Hello I got Lidar Data in the form of .asc

I know the part where you can load this to surface by going to surface definition and add DEM file.

However, I got 244 of these .asc file. Importing it one at a time will be time consuming. Considering each asc file is between 30mb to 35mb.

Is there a way to batch import these files? These DEM files are on a grid that ultimately , when combined, creates one big lidar survey. When I import them one a time in a vertical manner (8 files = 1 column), it works fine. But as soon as you go to the next column, it takes longer to process. As it tries to triangulate it with the rest of the first column of DEM files.

Any input will be greatly appreciated. Thanks.

[Alfred.NESWADBA]

Hi,

not sure about the import format, but I would start using ReCap and import them into ReCap, then for Civil 3D import/reference the pointcloud as one object (RPC file).

- alfred -

[TerryDotson]

ESRI Ascii Grids are not Lidar (they may be derived from Lidar).  The points will hit on a grid pattern (not left/right sweeps) and the points have no classification values.  Furthermore, if two columns (16 files) begins to slow Civil3D, the entire collection (of 244) may grind it to a halt.  Anything more than 30 million points seems to do that.  Then the triangulation as you mention is also on a grid pattern. 

If you don't need the entire area covered by the 244 files, consider importing only those needed.  Lastly, unless it's been added lately, the (grid file ASC) is not importable by Recap anyway.

[Anonymous]

I think if it was me I would take it to QGIS and Merge.  (QGIS is an open source GIS).  This would also allow you to down sample or boundary much easier than Civil 3d or ReCap. 

Depending on your desired use, down sampling might be advisable, this sounds like it is going to be a huge file with huge performance hits.

I have gone round and round with ReCap and find it basically a waste of my time.  Can't deal with many file types, doesn't understand classification, etc.

We have experimented with using Infraworks to import some lidar data, but it also has massive overhead.  It does a better job though.

Thanks,