[GRASS-user] Adding a semi-transparent layer

[Glynn Clements]

José Antonio Ruiz Arias wrote:

> on the map display of the GRASS gui is very easy to get a transparency
> effect on a layer, but I have been trying to do it exclusively by command
> line to script a task and I didn’t success. Does anyone know how can I solve
> this issue? The aim is to add a semi-transparent layer with climatological
> information above a terrain raster.

If you want the end result as an image, you can use the same mechanism
as gis.m uses, i.e. generate each layer as a PPM/PGM pair using the
PNG driver then combine them with g.pnmcomp.

If you need the result as a map, so that you can use it as a
background in an X monitor, use r.blend.

-- 
Glynn Clements <glynn at gclements.plus.com>