AlignmentScene R6 Class for Point Cloud Alignment

The `AlignmentScene` R6 class provides methods for aligning two 3D point clouds plots, typically from terrestrial (MLS/TLS) or aerial (ALS/UAV) LiDAR sources. It implements a multi-step alignment process with coarse, fine, and extra-fine alignment stages.

Methods

Public methods

Method new()

Create a new AlignmentScene object.

Usage

AlignmentScene$new(fref, fmov, radius = 20, verbose = TRUE)

Arguments

fref, fmov

character, path to the las laz file with the point cloud to align. fref is the reference point cloud, fmov is the point cloud to be aligned

radius

clip radius. The routine does not align the full point cloud but clip before to compute the registration matrix

verbose

logical

Returns

A new `AlignmentScene` object.

Method print()

print

Usage

AlignmentScene$print()

Method set_radius()

Set clip radius

Usage

AlignmentScene$set_radius(radius)

Arguments

radius

numeric.

Method set_ref_is_ground_based()

Tell the pipeline if the reference point cloud is ground-based (TLS, MLS)

Usage

AlignmentScene$set_ref_is_ground_based(val = TRUE)

Arguments

val

logical

Method set_mov_is_ground_based()

Tell the pipeline if the moving point cloud is ground-based (TLS, MLS)

Usage

AlignmentScene$set_mov_is_ground_based(val = TRUE)

Arguments

val

logical

Method prepare()

First function to run. It read the point cloud, extract features, and perform raw alignment

Usage

AlignmentScene$prepare()

Method coarse_align()

Second function to run. It perform a brute force alignment

Usage

AlignmentScene$coarse_align(res = 2, max_offset = 10, debug = FALSE)

Arguments

res

numeric. Subsampling resolution. Keep it as is.

max_offset

numeric. Maximum translation possible. Increase if the point cloud are strongly missaligned on XY.

debug

logical.

Method fine_align()

Third function to run. It perform an ICP alignment

Usage

AlignmentScene$fine_align(overlap = "auto", use_cc = FALSE)

Arguments

overlap

numeric trimmed ICP overlap. Can be 10, 20, 30, 40 to 100.

use_cc

bool. Use CloudCompare ICP instead of native ICP.

Method extra_fine_align()

Fourth function to run. It perform an ICP alignment on the trunks

Usage

AlignmentScene$extra_fine_align()

Method align()

Full pipeline

Usage

AlignmentScene$align(res = 2, max_offset = 8)

Arguments

res

numeric. Subsampling resolution. Keep it as is.

max_offset

numeric. Maximum translation possible. Increase if the point cloud are strongly missaligned on XY.

Method plot()

Plot alignment

Usage

AlignmentScene$plot(
  which = c("raw", "coarse", "fine", "extra"),
  compare_to = which
)

Arguments

which

string. The alignment level to plot

compare_to

string. The alignment level to plot and to compare

Method get_registration_matrix()

Get the registration matrix. This matrix is more or less accurate as a function of the level of registration performed

Usage

AlignmentScene$get_registration_matrix()

Method clone()

The objects of this class are cloneable with this method.

Usage

AlignmentScene$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.