makeAspect

Calculate a hillshde from a digital terrain model (DTM) using torch

Usage

makeHillshade(
  dtm,
  cellSize = 1,
  sunAzimuth = 315,
  sunAltitude = 45,
  doMD = FALSE,
  writeRaster = FALSE,
  outName,
  device = "cpu"
)

Arguments

dtm

Input SpatRaster object representing bare earth surface elevations.

cellSize

Resolution of raster grid. Default is 1 m.

sunAzimuth

Direction of illuminating source as a compass direction. Default is 315-degrees or northwest.

sunAltitude

Angle of illuminating source above the horizon from 0-degrees (horizon) to 90-degrees (zenith). Default is 45-degrees

doMD

TRUE or FALSE. Whether or not to generate a multidirectional hillshade. Default is FALSE.

writeRaster

TRUE or FALSE. Save output to disk. Default is TRUE.

outName

Name of output raster with full file path and extension.

device

"cpu" or "cuda". Use "cuda" for GPU computation. Without using the GPU, implementation will not be significantly faster than using non-tensor-based computation. Defaults is "cpu".

Details

Calculate a hillshade from a digital terrain model (DTM) using torch. User can specify a illuminating position using an aspect and altitude. A multidirectiontal hillshade is calculated by averaging hillshades with different sun positions ((north X 2Xnorthwest X west X southeast)/5.

Examples

if (FALSE) { # \dontrun{
pth <- "OUTPUT PATH"
dtm <- rast(paste0(pth, "dtm.tif"))
hsR <- makeHillshade(dtm,
cellSize=1,
sunAzimuth=315,
sunAltitude=45,
doMD = FALSE,
writeRaster=TRUE,
outName=paste0(pth, "hs.tif"), device="cuda")
} # }