On Thursday 03 of October 2013 11:44:38 Gregory Penn wrote: > I am attempting to create maps from the command line, which are composites > of several raster and vector layers.
Working on GRASS 6.x or 7? > In order to visualize the data effectively, I need to vary the opacity of > the layers. I have found that this is simple to achieve in the wxGUI, but > the GUI does not display the underlying module call as it does with many > other commands. A little Googling helped me to discover a module called > g.pnmcomp, which was apparently used by the old Tcl/Tk GUI for managing > layer opacity, but that module appears not to be intended for end users and > I suspect that there is an easier and more direct way to achieve my desired > results. Check r.blend: <http://grass.osgeo.org/grass64/manuals/r.blend.html>, <http://grass.osgeo.org/grass70/manuals/r.blend.html>. The latter features a "-c" flag, which does... "Combine resulting R,G,B layers into single output map". > The process by which I'm creating my maps is essentially this sequence of > commands (is there a better approach?): > > g.region rast=region_raster.tif > d.mon start=PNG > d.rast map=some_raster.tif > d.rast map=another_raster.tif > d.vect map=some_vector.shp > d.mon stop=PNG Ah, this is GRASS6.x then. I think you can still blend maps and then maybe use d.out.png to export? See <http://grass.osgeo.org/grass64/manuals/d.out.png.html>. > It seems to me that either d.mon or the PNG driver is doing the compositing > and so would handle the opacity of the layers, but I can't find any > documentation of how to specify values for opacity. This is surprising to > me because it seems that what I'm trying to do is such a basic and commonly > used operation in creating maps. What am I missing? Hope this is what you are looking for. Nikos _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
