[GRASSLIST:6342] convert vector to raster

GRASS GRASS user
1

Dears,
I was trying to make a 3D dysplay of a DEM with geology over it, but NVIZ
doesn't handle vector areas (color filed), so I figured out about convert my
vector geology to raster, but then I couldn't get the colors! I can set up a
single value, or a column in the table, but this col can't be GRASSRGB, which I
use to give me the right colors on screen.
How can I get this 3D-geology?

thanks all

Carlos
--
+----------------------------------------------------------+
          Carlos Henrique Grohmann - Guano
   Geologist M.Sc - Doctorate Student at IGc-USP - Brazil
        Linux User #89721 - guano at usp dot br
+----------------------------------------------------------+

2

Carlos,

You are almost there. Use the 'rules' option in r.colors to specify the
color you want for each value in your new raster map. Then you can do the
drape with the colors you want. For an ortho-view, create a shaded relief
map (under raster/terrain analysis in the menus). Then drape the colored
geology raster over it using d.his (display/display raster map in the
menus).

Michael

On 4/5/05 2:29 PM, "Carlos Henrique Grohmann" <guano@usp.br> wrote:

Dears,
I was trying to make a 3D dysplay of a DEM with geology over it, but NVIZ
doesn't handle vector areas (color filed), so I figured out about convert my
vector geology to raster, but then I couldn't get the colors! I can set up a
single value, or a column in the table, but this col can't be GRASSRGB, which
I
use to give me the right colors on screen.
How can I get this 3D-geology?

thanks all

Carlos

--
Michael Barton, Professor
School of Human Origins, Cultures, & Society
Arizona State University
Tempe, AZ 85287

Web - http://www.public.asu.edu/~cmbarton

3

Hi

I've got a question regarding the opposite situation. When I convert a colorfull integer raster (eg. landuse) to vector polygons, how can I preserve colors in the resulting polygon vector layer, ie. copy raster's RGB values to output's datatable GRASSRGB column?

Also, is it possible to assign colors to vector layer automaticaly in a similar way that r.colors does it for rasters? It's important for ps.map. So far I've been converting my polygon vectors to raster, r.colors, and ps.map then. How could I specify a colortable directly on a vector layer?

Maciek

----- Original Message ----- From: "Michael Barton" <michael.barton@asu.edu>
To: "Carlos Henrique Grohmann" <guano@usp.br>; "GRASS mailing list" <GRASSLIST@baylor.edu>
Sent: Wednesday, April 06, 2005 7:24 AM
Subject: [GRASSLIST:6343] Re: convert vector to raster

Carlos,

You are almost there. Use the 'rules' option in r.colors to specify the
color you want for each value in your new raster map. Then you can do the
drape with the colors you want. For an ortho-view, create a shaded relief
map (under raster/terrain analysis in the menus). Then drape the colored
geology raster over it using d.his (display/display raster map in the
menus).

Michael

On 4/5/05 2:29 PM, "Carlos Henrique Grohmann" <guano@usp.br> wrote:

Dears,
I was trying to make a 3D dysplay of a DEM with geology over it, but NVIZ
doesn't handle vector areas (color filed), so I figured out about convert my
vector geology to raster, but then I couldn't get the colors! I can set up a
single value, or a column in the table, but this col can't be GRASSRGB, which
I
use to give me the right colors on screen.
How can I get this 3D-geology?

thanks all

Carlos

--
Michael Barton, Professor
School of Human Origins, Cultures, & Society
Arizona State University
Tempe, AZ 85287

Web - http://www.public.asu.edu/~cmbarton

4

Maciek,

in ps.map you can specify the RGB color you want for vector areas, but you will
have to make one entry in you script file for each color (check out ps.map man
page). for example, in a geologic map:

vareas geology
layer 1
masked y
where lithology='sandstone'
label Sandstone
color black
fcolor 215:93:63
width 0.1
end

You do this for each lithology (or soil type, in your case)

Hope this helps

Carlos

--
+----------------------------------------------------------+
          Carlos Henrique Grohmann - Guano
   Geologist M.Sc - Doctorate Student at IGc-USP - Brazil
        Linux User #89721 - guano at usp dot br
+----------------------------------------------------------+

Citando Maciek Sieczka <werchowyna@epf.pl>:

Hi

I've got a question regarding the opposite situation. When I convert a
colorfull integer raster (eg. landuse) to vector polygons, how can I
preserve colors in the resulting polygon vector layer, ie. copy raster's RGB

values to output's datatable GRASSRGB column?

Also, is it possible to assign colors to vector layer automaticaly in a
similar way that r.colors does it for rasters? It's important for ps.map.
So far I've been converting my polygon vectors to raster, r.colors, and
ps.map then. How could I specify a colortable directly on a vector layer?

Maciek

----- Original Message -----
From: "Michael Barton" <michael.barton@asu.edu>
To: "Carlos Henrique Grohmann" <guano@usp.br>; "GRASS mailing list"
<GRASSLIST@baylor.edu>
Sent: Wednesday, April 06, 2005 7:24 AM
Subject: [GRASSLIST:6343] Re: convert vector to raster

> Carlos,
>
> You are almost there. Use the 'rules' option in r.colors to specify the
> color you want for each value in your new raster map. Then you can do the
> drape with the colors you want. For an ortho-view, create a shaded relief
> map (under raster/terrain analysis in the menus). Then drape the colored
> geology raster over it using d.his (display/display raster map in the
> menus).
>
> Michael
>
>
> On 4/5/05 2:29 PM, "Carlos Henrique Grohmann" <guano@usp.br> wrote:
>
>> Dears,
>> I was trying to make a 3D dysplay of a DEM with geology over it, but NVIZ
>> doesn't handle vector areas (color filed), so I figured out about convert

>> my
>> vector geology to raster, but then I couldn't get the colors! I can set
>> up a
>> single value, or a column in the table, but this col can't be GRASSRGB,
>> which
>> I
>> use to give me the right colors on screen.
>> How can I get this 3D-geology?
>>
>> thanks all
>>
>> Carlos
>
> --
> Michael Barton, Professor
> School of Human Origins, Cultures, & Society
> Arizona State University
> Tempe, AZ 85287
>
> Web - http://www.public.asu.edu/~cmbarton
>
>

5

Thank for your interest Carlos, but I meant how to:

1. assign a colortable to a vector layer, based on a given column of attributes (something like r.colors for rasters)
2. preserve the rasters colortable after v.to.rast in the resulting vector layer (having RGB codes stored in GRASSRGB column)

Has anybody got an idea how to achieve this fairly easily so it could be used for a daily work? Or would it require new functionality in Grass?

Maciek

----- Original Message ----- From: "Carlos Henrique Grohmann" <guano@usp.br>
To: "Maciek Sieczka" <werchowyna@epf.pl>
Cc: "GRASS mailing list" <GRASSLIST@baylor.edu>
Sent: Wednesday, April 06, 2005 1:56 PM
Subject: Re: [GRASSLIST:6343] Re: convert vector to raster

Maciek,

in ps.map you can specify the RGB color you want for vector areas, but you will
have to make one entry in you script file for each color (check out ps.map man
page). for example, in a geologic map:

vareas geology
layer 1
masked y
where lithology='sandstone'
label Sandstone
color black
fcolor 215:93:63
width 0.1
end

You do this for each lithology (or soil type, in your case)

Hope this helps

Carlos

--
+----------------------------------------------------------+
         Carlos Henrique Grohmann - Guano
  Geologist M.Sc - Doctorate Student at IGc-USP - Brazil
       Linux User #89721 - guano at usp dot br
+----------------------------------------------------------+

Citando Maciek Sieczka <werchowyna@epf.pl>:

Hi

I've got a question regarding the opposite situation. When I convert a
colorfull integer raster (eg. landuse) to vector polygons, how can I
preserve colors in the resulting polygon vector layer, ie. copy raster's RGB

values to output's datatable GRASSRGB column?

Also, is it possible to assign colors to vector layer automaticaly in a
similar way that r.colors does it for rasters? It's important for ps.map.
So far I've been converting my polygon vectors to raster, r.colors, and
ps.map then. How could I specify a colortable directly on a vector layer?

Maciek

----- Original Message ----- From: "Michael Barton" <michael.barton@asu.edu>
To: "Carlos Henrique Grohmann" <guano@usp.br>; "GRASS mailing list"
<GRASSLIST@baylor.edu>
Sent: Wednesday, April 06, 2005 7:24 AM
Subject: [GRASSLIST:6343] Re: convert vector to raster

> Carlos,
>
> You are almost there. Use the 'rules' option in r.colors to specify the
> color you want for each value in your new raster map. Then you can do > the
> drape with the colors you want. For an ortho-view, create a shaded > relief
> map (under raster/terrain analysis in the menus). Then drape the > colored
> geology raster over it using d.his (display/display raster map in the
> menus).
>
> Michael
>
> On 4/5/05 2:29 PM, "Carlos Henrique Grohmann" <guano@usp.br> wrote:
>
>> Dears,
>> I was trying to make a 3D dysplay of a DEM with geology over it, but >> NVIZ
>> doesn't handle vector areas (color filed), so I figured out about >> convert

>> my
>> vector geology to raster, but then I couldn't get the colors! I can >> set
>> up a
>> single value, or a column in the table, but this col can't be >> GRASSRGB,
>> which
>> I
>> use to give me the right colors on screen.
>> How can I get this 3D-geology?
>>
>> thanks all
>>
>> Carlos
>
> -- > Michael Barton, Professor
> School of Human Origins, Cultures, & Society
> Arizona State University
> Tempe, AZ 85287
>
> Web - http://www.public.asu.edu/~cmbarton
>

6

1. assign a colortable to a vector layer, based on a given column of
attributes (something like r.colors for rasters)
2. preserve the rasters colortable after v.to.rast in the resulting
vector layer (having RGB codes stored in GRASSRGB column)

r.to.vect?

Has anybody got an idea how to achieve this fairly easily so it could
be used for a daily work? Or would it require new functionality in
Grass?

You would have to write something that created a GRASSRGB column and
populated it with formatted output from the raster's colr/ file.

To do it in a shell script, you would probably have to use g.findfile,
g.tempfile, and some db code stolen from the v.in.garmin script as well
as the usual unix tools. Shouldn't be *too* bad.

Or do it properly in the C code for r.to.vect / v.to.rast if you can.

The other direction is even easier as you can pipe directly to r.colors.

Hamish