Interactive Transect Clipping with lidR

This function interactively clips a transect from a LAS dataset. It first generates a surface model (either a Canopy Height Model or a Digital Terrain Model) and displays it. The user is then prompted to click two points (start and end of the transect) on the plot. A transect polygon is constructed from these points and used to clip the LAS dataset.

Usage

clip_transect_interactive(
  las,
  width = 5,
  res = 1,
  subcircle = 0,
  plot_dtm = FALSE
)

Arguments

las

A character string specifying the path to a LAS/LAZ file or a LAS object.

width

Numeric. The width of the transect. Default is 5.

res

Numeric. The resolution for rasterizing the surface model. Default is 1.

subcircle

Numeric. Parameter for the p2r function used in canopy rasterization (CHM only). Default is 0.

plot_dtm

Logical. If TRUE, generates and plots a Digital Terrain Model (DTM) using rasterize_terrain for transect selection. If FALSE (default), a Canopy Height Model (CHM) is used. Note: DTM generation requires classified ground points for best results.

Value

A LAS object corresponding to the clipped transect.

Examples

if (FALSE) { # \dontrun{
  # use the Megaplot example dataset from lidR:
  lasFile <- system.file("extdata", "Megaplot.laz", package = "lidR")

  # Example 1: Interactive clipping using the default CHM
  las_clipped_chm <- clip_transect_interactive(
      las       = lasFile,
      width     = 5,
      res       = 1,
      subcircle = 0.25
    )

  # Example 2: Interactive clipping using a DTM
  # First, we need to read the LAS file and classify ground points
  las <- readLAS(lasFile)
  las <- classify_ground(las, algorithm = csf())

  las_clipped_dtm <- clip_transect_interactive(
      las       = las,
      width     = 10,
      res       = 1,
      plot_dtm  = TRUE
    )
} # }