When shading/illuminating terrain with grdimage -I
I run into the problem of the shading changing the saturation and thus the color and not just the brightness.
Additionally the shading is way too aggressive for my liking. Especially on the lighted side. I experimented quite a bit with grdgradient
but that brought me nowhere. After quite a bit of unsuccessful reading in the Docs I’m turning to you for your ideas, tips and tricks.
-
What I’m trying to duplicate. It seems it is handmade with quite a bit of artistic freedom. Therefore a 1:1 copy can’t be achieved as I think there is no way how I can selectively smoothen the flatter areas where detail is not necessary for me.
-
The plain colors of my CPT
-
My CPT with
-I+d
. Note the greens close to the shore line which became way more saturated und the very bright (white-ish) sunny side of the summit. One can argue that Hawai’i enjoys lots of sunshine and lush vegetation but that isn’t what I’m after.
My questions:
- How to keep the colors the same and only change their brightness?
- How to do I restrict the brightness of the lit side while keeping the darkening of the unlit side the same or even increase it?
Your input is greatly appreciated.
Some code to play with:
gmt grdcut @earth_relief_03s -Ghawaii.grd -R-156.5/-154.5/18.5/20.5
gmt begin sectional png
gmt set PS_LINE_CAP round
gmt set PS_LINE_JOIN round
gmt clip -R-156.5/-154.5/18.5/20.5 -Jm-155.5/1:500000 land_polygons_osm_hawaii.bf2 -bi2f -B+g232/252/254
gmt grdimage hawaii.grd -Cfaa.cpt -I+d
gmt grdcontour hawaii.grd -Cfaa.cpt -Wthinner,204/217/233
gmt clip -C
gmt plot land_polygons_osm_hawaii.bf2 -bi2f -Wthinner,7/72/135
gmt end
land_polygons_osm_hawaii.bf2.zip (104.8 KB)
faa.cpt.zip (759 Bytes)