[GRASS-user] Multidirectional hillshading scripts / addons?

[Carlos Henrique Grohmann de Carvalho]

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 at 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 at 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
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-- 
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/0000-0001-5073-5572
________________
Can’t stop the signal.
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