The hardware and bandwidth for this mirror is donated by dogado GmbH, the Webhosting and Full Service-Cloud Provider. Check out our Wordpress Tutorial.
If you wish to report a bug, or if you are interested in having us mirror your free-software or open-source project, please feel free to contact us at mirror[@]dogado.de.

Simulating Crook Deformations

Overview

This vignette shows how to apply crook deformations to LiDAR-derived stem point clouds using {crookR} (deformation-only).

library(crookR)
data("example_stem")

Example: XYZ point cloud for a single stem


library(crookR)
data("example_stem")
str(example_stem)
#> Classes 'data.table' and 'data.frame':   708145 obs. of  3 variables:
#>  $ X: num  0.28 0.28 0.28 0.28 0.28 ...
#>  $ Y: num  0.28 0.28 0.28 0.28 0.28 ...
#>  $ Z: num  0.01 0.01 0.02 0.02 0.02 ...
#>  - attr(*, ".internal.selfref")=<externalptr>
head(example_stem)
#>        X     Y     Z
#>    <num> <num> <num>
#> 1:  0.28  0.28  0.01
#> 2:  0.28  0.28  0.01
#> 3:  0.28  0.28  0.02
#> 4:  0.28  0.28  0.02
#> 5:  0.28  0.28  0.02
#> 6:  0.26  0.26  0.00

Single-direction deformation (krok_type = “1dir”)

A smooth lateral deviation of amplitude krok_deviation is applied over a vertical range of length krok_length, starting at krok_start.

stem_1dir <- crook_deform(
  x = example_stem,
  krok_length     = 0.5,
  krok_start      = 4.0,
  krok_type       = "1dir", 
  krok_deviation  = 0.08,   # try 0.05..0.12 for milder/stronger bends
  az              = 0,      # bend along +X
  spar            = 0.8
)

# Quick plan-view check

op <- par(mfrow = c(1,2), mar = c(3,3,2,1))
plot(example_stem$X, example_stem$Z, pch=16, cex=0.3, xlab="X (m)", ylab="Z (m)", main="Original")
plot(stem_1dir$X,     stem_1dir$Z,     pch=16, cex=0.3, xlab="X (m)", ylab="Z (m)", main="Crooked 1dir (az = 0°)")

par(op)

Double-direction deformation (krok_type = “2dir”) with inflection

The deviation changes direction at a fraction inflektion_X of the length (0 < inflektion_X < 1). inflektion_ext scales the amplitude after the inflection.

stem_2dir <- crook_deform( 
  x = example_stem,
  krok_length = 0.5,
  krok_start = 4.0,
  krok_type = "2dir",
  krok_deviation = 0.1,
  inflektion_X = 1/3,    # inflection at ~33% of the deformed length
  inflektion_ext = 1/2,    # second leg amplitude relative to first
  az = 0,     
  spar = 0.8
  )

op <- par(mfrow = c(1,2), mar = c(3,3,2,1))
plot(example_stem$X, example_stem$Z, pch=16, cex=0.3, xlab="X (m)", ylab="Z (m)", main="Original")
plot(stem_2dir$X,     stem_2dir$Z,     pch=16, cex=0.3, xlab="X (m)", ylab="Z (m)", main="Crooked 2dir (ip = 0.33)")

par(op)

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.
Health stats visible at Monitor.