I am presently using LAStools to analyse LiDAR data. Can LAStools classify the points into various features such as vegetation, roads, buildings etc? If so, how is it done?
LASTools can perform a ground classification using "lasground" and then can perform some limited feature classification using "lasclassify". The performance and quality of feature classification in point clouds is strongly influenced by the type of landscape collected. Some landscapes just do not lend themselves to acceptable automated results. The best feature classification is provided when the vendor performs a "hands on" approach where considerable editing is performed after a given ground/feature classification algorithm is applied.
I am not sure how many tools are implemented in the ArcGIS LAS Toolbox. You may want to look at the available LAS commandline executable tools for more detailed analysis.
If your data was collected in an area with forest canopy or topographic relief I would recommend using the MCC algorithm for ground classification. This method uses a Thin Plate Spline and produces very good results. I am not overly fond of TIN based methods because of the surface bias, distortion and noise that they tend to produce.
lasclassify tool, be aware the .las files need
to already have ground points classified and point heights computed*.
See examples from lasclassify README:
lasground -i lidar.las -o lidar_with_bare_earth.las -city lasheight -i lidar_with_bare_earth.las -o lidar_with_heights.las lasclassify -i lidar_with_heights.las -o lidar_classified.las
Finds the ground points with lasground, computes the height of each point with lasheight, and classifies buildings and high vegetation with the default settings.
*To 'compute point heights' is also known as 'normalizing'. For example, see: Normalizing point cloud data.
Alternatively, one might find useful the Google Groups: LAStools - efficient tools for LiDAR processing, which is led by LAStools' developer Martin Isenburg.