Surface Lidar Extract

This tool lets you extract objects directly from a classified lidar data file.

Keyboard Command: SurLidExt

• Class: Sets the current lidar class to search for, the default is always 2 (ground).
• Drape: Sets the elevation of each vertex of a 3D object (such as 3dPolylines) to the elevation at the point.
• Profile: Draws a static profile by picking points to show the profile direction.
• Spots:
  • Nearest: Draws a static spot elevation at the nearest existing lidar point.
  • Picked: Draws a static spot elevation at the absolute point picked.
• eXit: Exits the command when all desired options are complete.

Procedure:

1. Open the drawing containing related geometry.
2. Initiate the tool from the menu, ribbon, or command.
3. Select the lidar file to use (see notes).
4. Designate a process to perform from the command line options.

Notes:

• To speed up the loading of lidar data in subsequent runs, this tool created a temporary cache file containing the minimum information (including indexes) needed and stores it in a file with the same name except for a .TMP file extension. This content is loaded in secondary runs and loads much quicker. At any time you can delete this .TMP file and it will be recreated later.
• Most tools work by determining a minimum number of adjacent (search radius) lidar points which are then triangulated 'on the fly' to determine the actual elevation. This temporary triangulation is very fast and discarded afterwards.
• A related process (sampling of lidar to produce cross sections) is a separate tool called Section Sample Lidar.