QGIS Algorithm provided by GRASS r.viewshed (grass:r.viewshed). Computes the viewshed of a point on an elevation raster map.

grass_r_viewshed(
  input = qgisprocess:::qgis_default_value(),
  coordinates = qgisprocess:::qgis_default_value(),
  observer_elevation = qgisprocess:::qgis_default_value(),
  target_elevation = qgisprocess:::qgis_default_value(),
  max_distance = qgisprocess:::qgis_default_value(),
  refraction_coeff = qgisprocess:::qgis_default_value(),
  memory = qgisprocess:::qgis_default_value(),
  .c = qgisprocess:::qgis_default_value(),
  .r = qgisprocess:::qgis_default_value(),
  .b = qgisprocess:::qgis_default_value(),
  .e = qgisprocess:::qgis_default_value(),
  output = qgisprocess:::qgis_default_value(),
  GRASS_REGION_PARAMETER = qgisprocess:::qgis_default_value(),
  GRASS_REGION_CELLSIZE_PARAMETER = qgisprocess:::qgis_default_value(),
  GRASS_RASTER_FORMAT_OPT = qgisprocess:::qgis_default_value(),
  GRASS_RASTER_FORMAT_META = qgisprocess:::qgis_default_value(),
  ...,
  .complete_output = .complete_output_option(),
  .quiet = .quiet_option(),
  .messages = .message_option()
)

Arguments

input

raster - Elevation. Path to a raster layer.

coordinates

point - Coordinate identifying the viewing position. Point coordinate as an 'x,y' string, e.g. '1.5,10.1'.

observer_elevation

number - Viewing elevation above the ground. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

target_elevation

number - Offset for target elevation above the ground. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

max_distance

number - Maximum visibility radius. By default infinity (-1). A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

refraction_coeff

number - Refraction coefficient. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

memory

number - Amount of memory to use in MB. A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

.c

boolean - Consider earth curvature (current ellipsoid). 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -c.

.r

boolean - Consider the effect of atmospheric refraction. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -r.

.b

boolean - Output format is invisible = 0, visible = 1. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -b.

.e

boolean - Output format is invisible = NULL, else current elev - viewpoint_elev. 1 for true/yes. 0 for false/no. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression. Original algorithm parameter name: -e.

output

rasterDestination - Intervisibility. Path for new raster layer.

GRASS_REGION_PARAMETER

extent - GRASS GIS region extent. A comma delimited string of x min, x max, y min, y max. E.g. '4,10,101,105'. Path to a layer. The extent of the layer is used..

GRASS_REGION_CELLSIZE_PARAMETER

number - GRASS GIS region cellsize (leave 0 for default). A numeric value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

GRASS_RASTER_FORMAT_OPT

string - Output Rasters format options (createopt). String value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

GRASS_RASTER_FORMAT_META

string - Output Rasters format metadata options (metaopt). String value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.

...

further parameters passed to qgisprocess::qgis_run_algorithm()

.complete_output

logical specifying if complete out of qgisprocess::qgis_run_algorithm() should be used (TRUE) or first output (most likely the main) should read (FALSE). Default value is TRUE.

.quiet

logical specifying if parameter .quiet for qgisprocess::qgis_run_algorithm() Default value is TRUE.

.messages

logical specifying if messages from qgisprocess::qgis_run_algorithm() should be printed (TRUE) or not (FALSE). Default value is FALSE.

Details

Outputs description

  • output - outputRaster - Intervisibility