POV-Ray : Newsgroups : povray.general : Rendering in B&W? : Re: Rendering in B&W? Server Time
12 Aug 2024 07:17:27 EDT (-0400)
  Re: Rendering in B&W?  
From: Roland Mas
Date: 12 Mar 1999 11:21:46
Message: <m3bthy1xwl.fsf@clodomir.rezel.enst.fr>
Nieminen Mika <war### [at] cctutfi> writes:

>   How do you model this:
> 
>   Three objects: One is yellow, one is cyan and one is white.
>   Two light sources: One is red and the other is blue.
>   Of course the red light source only illuminates the yellow and the white
> object while the blue light source only illuminates the cyan and also
> the white object.
>   I want this image in b/w.

I wondered how long it would take until someone would notice this...
I'm afraid you all lost :-)

The doc says it all (almost):

--- Cut here ---
7.8.4            HF_Gray_16

The hf_gray_16 setting is useful when using POV-Ray to generate
heightfields for use in other POV-Ray scenes. The syntax is...

  global_settings { hf_gray_16 BOOLEAN }


The boolean value turns the option on or off. If the keyword is
specified without the boolean value then the option is turned on. If
hf_gray_16 is not specified in any global_settings statement in the
entire scene then the default is off.

When hf_gray_16 is on, the output file will be in the form of a
heightfield, with the height at any point being dependent on the
brightness of the pixel.  The brightness of a pixel is calculated in
the same way that color images are converted to grayscale images:

  height = 0.3 * red + 0.59 * green + 0.11 * blue


Setting the hf_gray_16 option will cause the preview display, if used,
to be grayscale rather than color. This is to allow you to see how the
heightfield will look because some file formats store heightfields in
a way that is difficult to understand afterwards. See section "Height
Field" for a description of how POV-Ray heightfields are stored for
each file type.
--- Cut here ---

Maybe it should have been a bit clearer.  Anyway, the output is (at
least in Targa Truevision format) a sixteen bit per pixel black and
white image file.

Roland.
-- 
Roland Mas


- Genki desu, ture en zinc.


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