Re: [GRASS-user] Multidirectional hillshading scripts / addons?
Hi HB, Here is one more: r.shaded.pca - Creates relief shades from various directions and combines them into RGB composition. https://grass.osgeo.org/grass8/manuals/addons/r.shaded.pca.html Best Markus On Fri, Feb 16, 2024 at 11:20 PM B H via grass-user wrote: > > Hi, > I am trying to create a hillshading effect using DEM rasters similar to ESRI > multidirectional hillshading, but I am unable to get anything in. grass to > perform as good as ESRI (or even gdaldem multidirectional shading). > I am hoping someone in this group has some scripts /addon/tips that I can try. > > So far I have tried the following on a few DEMs ( from 3m to 100 m grid > sizes). > 1) gdaldem multidirectional hillshading : It's not grass based, but so far > has performed better than other grass options : with the parameter zfactor > between 1 and 10. But it does not seem to be quite as good as ESRI. > 2) Following code is based on some old discussion on this email list.(Its > seems to exaggerate the hills and valleys more than I would expect) > https://gist.github.com/amcox/b54d65f08fe4448840462901fd6350d4 > 3) Other variants of hillshading like r.skyview : Tried with several > parameters but it seems to be inferior to gdaldem (It seems to be a 'washed > out' version of the multidirectional. hillshading). > > Thanks, > HB > ___ > grass-user mailing list > grass-user@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-user -- Markus Neteler, PhD https://www.mundialis.de - company https://grass.osgeo.org - FOSS https://neteler.org - freelancing & blog ___ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Multidirectional hillshading scripts / addons?
WhiteBox is another option (there is a QGIS plugin) https://www.whiteboxgeo.com/manual/wbt_book/available_tools/geomorphometric_analysis.html#MultidirectionalHillshade Carlos On Sat, Feb 17, 2024 at 10:44 AM Paulo van Breugel via grass-user < grass-user@lists.osgeo.org> wrote: > Hi, > > Not sure about grass gis, but have you tried the multidirectional option > when styling a raster as a hillshade in QGIS? See > https://bnhr.xyz/2019/01/22/hillshade-in-qgis.html. > > Cheers, > > Paulo > > > > > > On Fri, Feb 16, 2024 at 11:20 PM B H via grass-user < > grass-user@lists.osgeo.org> wrote: > >> Hi, >> I am trying to create a hillshading effect using DEM rasters similar to >> ESRI multidirectional hillshading, but I am unable to get anything in. >> grass to perform as good as ESRI (or even gdaldem multidirectional shading). >> I am hoping someone in this group has some scripts /addon/tips that I can >> try. >> >> So far I have tried the following on a few DEMs ( from 3m to 100 m grid >> sizes). >> 1) gdaldem multidirectional hillshading : It's not grass based, but so >> far has performed better than other grass options : with the parameter >> zfactor between 1 and 10. But it does not seem to be quite as good as ESRI. >> 2) Following code is based on some old discussion on this email list.(Its >> seems to exaggerate the hills and valleys more than I would expect) >> https://gist.github.com/amcox/b54d65f08fe4448840462901fd6350d4 >> 3) Other variants of hillshading like r.skyview : Tried with several >> parameters but it seems to be inferior to gdaldem (It seems to be a 'washed >> out' version of the multidirectional. hillshading). >> >> Thanks, >> HB >> ___ >> grass-user mailing list >> grass-user@lists.osgeo.org >> https://lists.osgeo.org/mailman/listinfo/grass-user >> > ___ > grass-user mailing list > grass-user@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-user > -- Prof. Carlos Henrique Grohmann Institute of Energy and Environment - Univ. of São Paulo, Brazil Editor-in-Chief - Brazilian Journal of Geology http://carlosgrohmann.com https://spamlab.github.io/ http://orcid.org/-0001-5073-5572 Can’t stop the signal. ___ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Multidirectional hillshading scripts / addons?
Hi, Not sure about grass gis, but have you tried the multidirectional option when styling a raster as a hillshade in QGIS? See https://bnhr.xyz/2019/01/22/hillshade-in-qgis.html. Cheers, Paulo On Fri, Feb 16, 2024 at 11:20 PM B H via grass-user < grass-user@lists.osgeo.org> wrote: > Hi, > I am trying to create a hillshading effect using DEM rasters similar to > ESRI multidirectional hillshading, but I am unable to get anything in. > grass to perform as good as ESRI (or even gdaldem multidirectional shading). > I am hoping someone in this group has some scripts /addon/tips that I can > try. > > So far I have tried the following on a few DEMs ( from 3m to 100 m grid > sizes). > 1) gdaldem multidirectional hillshading : It's not grass based, but so > far has performed better than other grass options : with the parameter > zfactor between 1 and 10. But it does not seem to be quite as good as ESRI. > 2) Following code is based on some old discussion on this email list.(Its > seems to exaggerate the hills and valleys more than I would expect) > https://gist.github.com/amcox/b54d65f08fe4448840462901fd6350d4 > 3) Other variants of hillshading like r.skyview : Tried with several > parameters but it seems to be inferior to gdaldem (It seems to be a 'washed > out' version of the multidirectional. hillshading). > > Thanks, > HB > ___ > grass-user mailing list > grass-user@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-user > ___ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user
