them thar hills

shadin’, texturin’, blendin’

Ross McDonald @mixedbredie

Take one DEM

Intermap 10m DTM

Add a colour gradient

Make a hill shade

Note the hatching effect caused by live hill shade renderer

Multiply blend

What is texture shading?

An alternative shaded relief technique Based on fractional Laplacian algorithms Emphasises drainage network Highlights the visual hierarchy Developed by Leland Brown Open source under BSD 2-clause www.textureshading.com Mac and Win binaries, compile on Linux

Take one DEM

Workflow

Convert GeoTIFF to GridFloat gdal_translate –of EHdr –ot Float32 in.tif out.flt

Generate a texture ./texture 2/3 out.flt texture.flt

Export a GeoTIFF ./texture_image +2.0 texture.flt texture.tif

Texture shaded DEM

Coloured in

Blended with hill shade

Without texture shade

Blender 3D

OS Terrain50 DTM See https://wanderingcartographer.wordpress.com/ for workflows

Uses the BlenderGIS addon - https://github.com/domlysz/BlenderGIS

Comparison

QGIS/GDAL Quick

Easy

QGIS Raster menu

QGIS Live renderer (press F7 in 2.16)

Render artefacts

Texture Shading Download required

Easy to use

Some prep needed (Float32 DEM)

Memory dependent

Nice effect

Use alone or blend

Blender Separate app Steep learning curve More prep needed (Int16 DEM) RAM/CPU/GPU dependent Slow but lovely Realistic lighting

Inspiration

http://www.shadedrelief.com/ http://www.reliefshading.com/ https://wanderingcartographer.wordpress.com/ http://mapzilla-art.co.uk/ https://owenpowell.wordpress.com/ http://www.mapsmith.net/ https://somethingaboutmaps.wordpress.com/ https://cartoblography.wordpress.com/ http://christopherwesson.azurewebsites.net/