Interactive Processing and Segmentation of Forest TLS Point-Cloud Data R package PiC version 3.3.3 Tools for the processing, segmentation, and analysis of terrestrial laser scanning (TLS and MLS) forest point-cloud data. The package provides fast voxel-based processing, classification of point clouds into forest floor, understory, canopy, and woody components, and algorithms for single-tree analysis and structural characterization. Methods are designed to handle large and dense point-cloud datasets efficiently, supporting applications in forest structure assessment, connectivity analysis, and fire-risk evaluation. Input data are provided as '.xyz', '.txt', '.las', or '.laz' point-cloud files. The circle-fitting routines used for diameter estimation are adapted, in base R, from the 'conicfit' package (GPL-3) by Jose Gama, based on the original algorithms and code by Nikolai Chernov. For methodological details, see Ferrara and Arrizza (2025) <https://hdl.handle.net/20.500.14243/533471> and Ferrara et al. (2018) <doi:10.1016/j.agrformet.2018.04.008>. Software Depends: R (>= 4.3) Imports: collapse, data.table, dbscan, dplyr, magrittr, RANN, stats, tictoc, terra, tools, utils Suggests: DT, fs, ggplot2, lidR, grid, gridExtra, later, plotly, shiny, shinycssloaders, shinydashboard, shinydashboardPlus, shinyFeedback, shinyFiles, shinyjs, shinythemes, scales, shinyWidgets, testthat (>= 3.0.0), tidyr, viridis, withr Roberto Ferrara <roberto.ferrara@cnr.it> Comprehensive R Archive Network (CRAN) Roberto Ferrara [aut, cre] (ORCID: <https://orcid.org/0009-0000-3627-6867>), Stefano Arrizza [ctb] (ORCID: <https://orcid.org/0009-0009-2290-3650>), Nikolai Chernov [cph] (Author of the original circle-fitting algorithms and code), Jose Gama [ctb] (Author of the R implementation of the circle-fitting code in the 'conicfit' package) GPL (>= 3) 2026-07-29 application/tgz https://CRAN.R-project.org/package=PiC doi:10.32614/CRAN.package.PiC