ferrellsl

I've found that MCC-LIDAR does a very good job at classifying ground returns but it's very slow and doesn't support compressed LAS/LAZ. To that end, I've written a GUI version of the excellent PDAL automated ground classification tool. It supports compressed LAS/LAZ files and is significantly faster than MCC-LIDAR. You can download the PDAL automated ground classification tool here: PDAL Automated Ground Classification There's also a version for MacOS/OSX. If any Mac users would like a copy, please contact me via my web page here: Contact

Many of my clients have been supplied with LAS and LAZ files that haven't had any ground point return classifications performed on them which makes it nearly impossible generate a contour map or surface model. There's a great open source tool called MCC-LIDAR which performs this function very well but it is a command line app and only compiled for 32-bit systems so the number of points it can handle is somewhat limited. There are a couple commercial products that perform ground classification but they are extremely costly and some even require annual subscriptions. I've written a GUI version of MCC-LIDAR and compiled it for 64-bit editions of Windows and released it as freeware. It has successfully classified the ground returns on a file with 83+ million points and should have no trouble on larger point clouds/point sets. You can download a copy here: MCC-LIDAR GUI and see my other apps here: LIDAR Widgets

I've just updated a few tools for working with LAS/LAZ files and added a couple new tools. My LAS to DXF point cloud tool now converts a LAS point cloud to a DXF point cloud and preserves the classification of the laser returns. I.e. LIDAR ground returns are classified as a 2 so all ground returns are placed on layer 2 during the conversion process. Vegetation is classified as 3, 4, or 5 for Low, Medium or High Vegetation and are placed on layers, 3, 4, and 5 respectively. The batch conversion tool has also been updated to support LIDAR classification. I've added a LAS Feature Extraction Tool. This tool will allow the user to extract/export any or all 18 LAS classifications from a LAS point cloud so that they can be modeled/mapped independently of each other. For example, all vegetation can be extracted for modeling or study, or all roads, railways and bridges can be extracted for traffic studies. Of course it also allows the user to extract just the ground returns for terrain modeling or mapping as well. See the feature extraction tool here: http://lidarwidgets.com/#!page-feature-extraction Another tool that I've added is called Mesh2Contour. It allows the user to create contour maps in DXF format from a mesh file that was created by my LAS to Mesh generation tools. See an output example here: http://lidarwidgets.com/#!page-2dcontours

I just made a minor update to the LAStoDXF-TIN app. On some systems it would fail during DXF creation. This has now been fixed. You can still grab a copy here: http://lidarwidgets.com/#!page-freestuff

I've have several requests for an application that extracts the ground returns from a LAS/LAZ file so that the ground could be modeled separately without any vegetation or structures on it. In response, I've written a new app called LAStoGround-XYZ that it will extract all the ground returns from a LAS/LAZ file and place them in an XYZ text file suitable for meshing or TIN'ing. I'm also giving away for free another app called LAStoDXF-TIN. It will create a TIN from a LAS/LAZ and generate a DXF as output. You can get copies for OS X and Windows here: http://lidarwidgets.com/#!page-freestuff

I've also just completed writing an application the converts a LAS point cloud into a DXF point cloud. See: http://lidarwidgets.com

There are a couple approaches for creating a DXF from LIDAR points. As you noted earlier, TINS created from LIDAR are so large as to make AutoCAD virtually unusable. The other option is to create a quadrilateral mesh from the points which will yield a much smaller but just as accurate model. I've written two applications to convert LAS files to an AutoCAD DXF. One outputs a TIN while the other outputs a mesh. The mesh generation app can process over 50 million points in less than 3 minutes. The TIN'ing app is slightly slower. See my website at http://lidarwidgets.com for more info or you an email me at: [email protected]