Hi and here's the second question,
I post it in two emails because I think it's easier to response to every separate email.
I got some vector lines (with z- values) and I got a raster surface. I need to know if the lines are above, intersecting or under the surface. Is it possible to that in GRASS? And if so, how is the trick?
Every help would be great!
Malte
On Sat, Mar 13, 2010 at 9:07 PM, Malte Martin <malte@perlomat.de> wrote:
...
I got some vector lines (with z- values) and I got a raster surface. I need
to know if the lines are above, intersecting or under the surface. Is it
possible to that in GRASS? And if so, how is the trick?
I hoped to suggest v.to.rast with the use=z parameter to you but it
only works for contour lines.
IMHO we need a 3D version of the G_plot_line2() function [1] to keep
also the Z value. This function is called in plot_line() in v.to.rast.
Maybe there is another possibility - but I think that this functionality in
v.to.rast would be useful.
After having obtained the raster map from the 3D vector line(s), the
rest is a simple r.mapcalc operation.
Markus
[1] http://download.osgeo.org/grass/grass6_progman/plot_8c.html#a8e856de4632aa9b8a679737ffb71631f