makeHillshade: makeAspect

In geodl: Geospatial Semantic Segmentation with Torch and Terra

makeAspect

Description

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

## Not run: 
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")

## End(Not run)

geodl documentation built on Nov. 12, 2025, 5:07 p.m.