d_visibility: Computes the directional visibility from a single location in...

In Blecigne/viewshed3d: Compute Viewshed in 3D Point Clouds of Ecosystems

Computes the directional visibility from a single location in a 3D point cloud

Description

Similar to the visibility function but allow to segment the viewshed by azimuth and elevation to analyze visibility in a given direction.

Usage

d_visibility(
  data,
  position,
  angular_res,
  elevation_range,
  azimuth_range,
  scene_radius,
  store_points
)

Arguments

data	LAS class object containing the xyz coordinates of a 3D point cloud.
position	vector of length 3 containing the xyz coordinates of the animal location. Default = c(0,0,0).
angular_res	numeric. The angular resolution of a single sightline. Default = 1.
elevation_range	(optional) numeric vector. The elevation range used to segment the viewshed. Range between 0 and 180.
azimuth_range	(optional) numeric vector. The azimuth range used to segment the viewshed. Range between 0 and 360.
scene_radius	(optional) numeric. Defines the radius of the scene relative to the animal position. Can be used to apply a cut-off distance to visibility analyses.
store_points	logical. If TRUE, the 3D point cloud is returned with visible and not visible points classified (see details in visibility).

Value

Similar to those of Similar of the visibility function.

Note

If elevation_range and azimuth_range are not defined, the outputs are similar to those obtained with the visibility function but the computation is less efficient.

Examples

# produce a spherical point cloud
sph <- lidR::LAS(generate_sphere(angular_res = 0.1,r = 1.5))


# compute visibility without segmentation
view.data <- d_visibility(data = sph,
                         position = c(0,0,0),
                         angular_res = 1,
                         store_points = TRUE,
                         scene_radius = 2)

# plot the viewshed
lidR::plot(view.data$points,colorPalette = "darkgreen")

# compute visibility segmented by elevation
view.data <- d_visibility(data = sph,
                         position = c(0,0,0),
                         angular_res = 1,
                         store_points = TRUE,
                         scene_radius = 2,
                         elevation_range = c(80,100))

# plot the viewshed
lidR::plot(view.data$points,colorPalette = "darkgreen")

# compute visibility segmented by azimuth
view.data <- d_visibility(data = sph,
                         position = c(0,0,0),
                         angular_res = 1,
                         store_points = TRUE,
                         scene_radius = 2,
                         azimuth_range = c(85,105))

# plot the viewshed
lidR::plot(view.data$points,colorPalette = "darkgreen")

# compute visibility segmented by azimuth and elevation
view.data <- d_visibility(data = sph,
                          position = c(0,0,0),
                          angular_res = 1,
                          store_points = TRUE,
                          scene_radius = 2,
                          azimuth_range = c(350,10),
                          elevation_range = c(80,100))

# plot the viewshed
lidR::plot(view.data$points,colorPalette = "darkgreen")

Blecigne/viewshed3d documentation built on Nov. 5, 2022, 9:08 p.m.