Hello,
I was wondering if there is a trick or even a module which enables transparency on a vector poligon (with rasters I guess you can use a trick with the hue-saturation module). I saw Radim's qgis implementation of GRASS rasters and vectors, including alpha blending (http://mpa.itc.it/radim/qgis/) so I was wandering if something similar is/will be/might be implemented in GRASS
Thanks
Francesco Pirotti
CIRGEO -University of Padua
phone. 049 - 8272522
fax. 049-8272686
cel. 328-2126861
francesco.pirotti@unipd.it
francesco.pirotti wrote:
I was wondering if there is a trick or even a module which enables
transparency on a vector poligon (with rasters I guess you can use a trick
with the hue-saturation module). I saw Radim's qgis implementation of
GRASS rasters and vectors, including alpha blending
(http://mpa.itc.it/radim/qgis/) so I was wandering if something similar
is/will be/might be implemented in GRASS
Nothing like that currently exists in the display architecture, and
isn't likely to be added any time soon.
The simplest solution is to convert everything to rasters, and either:
a) export the rasters to a standard image format (e.g. PPM), and use a
paint program (or image processing utilities such as pbmplus/netpbm)
to blend them,
b) use d.his or r.his, or
c) use r.mapcalc.
--
Glynn Clements <glynn.clements@virgin.net>
On Sat, Feb 07, 2004 at 12:10:53PM +0100, francesco.pirotti wrote:
Hello,
I was wondering if there is a trick or even a module which enables
transparency on a vector poligon (with rasters I guess you can use a trick
with the hue-saturation module). I saw Radim's qgis implementation of
GRASS rasters and vectors, including alpha blending
(http://mpa.itc.it/radim/qgis/) so I was wandering if something similar
is/will be/might be implemented in GRASS
Hi Francesco,
once there have been efforts to implement alpha blending into XDriver
(together with some RGB updates, maps as selectable layers etc):
Check
src.todo/display_driver/
Maybe the code is useful to re-implement these changes into
the current XDRIVER. It was never finished unfortunately.
Markus
Markus Neteler wrote:
> I was wondering if there is a trick or even a module which enables
> transparency on a vector poligon (with rasters I guess you can use a trick
> with the hue-saturation module). I saw Radim's qgis implementation of
> GRASS rasters and vectors, including alpha blending
> (http://mpa.itc.it/radim/qgis/) so I was wandering if something similar
> is/will be/might be implemented in GRASS
Hi Francesco,
once there have been efforts to implement alpha blending into XDriver
(together with some RGB updates, maps as selectable layers etc):
Check
src.todo/display_driver/
I don't see anything in that which relates to alpha blending.
--
Glynn Clements <glynn.clements@virgin.net>