| Re: Some questions on cgsurf and cgsurface [message #76964 is a reply to message #76961] |
Wed, 20 July 2011 14:09   |
penteado
Messages: 866
Registered: February 2018
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Senior Member
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Ok, thanks for the help.
On Jul 20, 5:13 pm, David Fanning <n...@dfanning.com> wrote:
> Paulo Penteado writes:
>> I have been trying to make shaded surfaces with CG, and encountered a
>> few difficulties, which perhaps have obvious solutions for those who
>> can find their way around the CG routines:
>
>> I tried to follow the examples with
>
>> data=dist(200)
>> loadct,33
>> cgwindow,'cgsurf',data,/shaded
>> cgcontrol,create_ps='cgtest.ps'
>
>> Which results in a file with a red background. The same if using the
>> menu in the window.
>
> Yes, this is because shaded surfaces are really
> images with axes overlayed on them. To get a white
> background, you will have to do something like this:
>
> data=dist(200)
> loadct,33, ncolors=254
> set_shading, values=[0,254]
> tvlct, 255, 255, 255, 255
> cgwindow,'cgsurf',data,/shaded
> cgcontrol,create_ps='cgtest.ps'
>
>> Also, am I correct in thinking that all ps output is only bitmap? It
>> is what it looked like from what I saw in the code.
>
> A shaded surface is a bitmap, because what is returned
> from SHADE_SURF is an image. Most other graphic output
> is vectorized.
>
>> Then I tried cgsurface:
>
>> data=dist(200)
>> loadct,33
>> cgsurface,data,/shaded
>
>> Which does make a much nicer looking ps file, which also matches what
>> I see in the screen. But I could not find a way to programmatically
>> make the file. And it also seems to only make bitmaps, at a fixed
>> resolution.
>
> Yes, there is no current way to create a PostScript file
> programmatically. And, to make things easy, the
> resolution is set to the window size. I am not sure
> if this can be vectorized, and I can't research it right
> now, as I am getting ready to leave Africa in a few hours.
>
> I'm planning a report on the lion roaring outside my
> hut, just 15 feet from my unlock screened door, and
> the cheetah I saw in the wild! :-)
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming:http://www.dfanning.com/
> Sepore ma de ni thue. ("Perhaps thos speakest truth.")
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