I'm a total grass newbie. When I drape a map over my base dem map the "draped" map blows away my colors in the dem map. Even where the drape map doesn't appear to have any values. (the dem map seems to get a sort of grey tone in those areas) Is there a way to preserve the color map from my base map and have the drape map only overlay the colors where it actually has values? ie: is there a transparency color i can set? the "(transparent null value cells)" checkbox doesn't seem to change anything.
I'm a total grass newbie. When I drape a map over my base dem map the
"draped" map blows away my colors in the dem map. Even where the drape
map doesn't appear to have any values. (the dem map seems to get a sort
of grey tone in those areas) Is there a way to preserve the color map
from my base map and have the drape map only overlay the colors where it
actually has values? ie: is there a transparency color i can set? the
"(transparent null value cells)" checkbox doesn't seem to change anything.
In the GUI, if you specify a "drape" map, it uses d.his (rather than
d.rast), with the "base" map used for the intensity (i_map= option)
and the "drape" map used for the hue (h_map=). In that case, the base
map should be grey-scale (typically the aspect map produced by
r.slope.aspect); also, the "transparent null value cells" option
doesn't work with d.his.
If you just want to overlay multiple maps, create a separate layer for
each map, with the "transparent" option enabled for all of the upper
layers.