Does one of the inofficial versions or even POV 3.5 support specular
mapping (i.e. controlling the reflectivity of a surface through the grey
value of an image file, analogous to height fields)? Would be nice,
wouldn't it?

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Jakob Tendel wrote:
> 
> Does one of the inofficial versions or even POV 3.5 support specular
> mapping (i.e. controlling the reflectivity of a surface through the grey
> value of an image file, analogous to height fields)? Would be nice,
> wouldn't it?

Yes and no.  Reflection and specularity are controlled by the finish{}
block and you can't use an image_map in the finish{} block.  However,
you can define multiple textures that have different finishes and apply
a material_map.

-- 
Francois Labreque | Make you a deal, I'll show you mine if you show 
    flabreque     | me yours.
        @         | 
   videotron.ca   |   - Pandora.

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Jakob Tendel wrote:
> 
> Does one of the inofficial versions or even POV 3.5 support specular
> mapping (i.e. controlling the reflectivity of a surface through the grey
> value of an image file, analogous to height fields)? Would be nice,
> wouldn't it?

That would be possible with a finish_map, similar to normal_map and
pigment_map - an often discussed suggestion.

It is not yet implemented, but it should be possible although it is
probably quite a lot of work.  

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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The specific instance, where this problem cropped up was: I wanted to create
a shiny metal sphere with pitted rusty areas scattered over the surface. I
used a layered texture for the shiny metal and rust respectively, but the
raytrace used only the finish values of the uppermost layer. So either I had
a dull metal or shiny rust, both of which was unsatisfying. If one could
control reflectivity with a grey image, one could overlay a corresponding
image-map and hopefully achieve much better results.

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Jakob Tendel <jak### [at] studentmetfu-berlinde> wrote in message
news:3ADD7773.494BE3A8@student.met.fu-berlin.de...
> The specific instance, where this problem cropped up was: I wanted to
create
> a shiny metal sphere with pitted rusty areas scattered over the surface. I
> used a layered texture for the shiny metal and rust respectively, but the
> raytrace used only the finish values of the uppermost layer. So either I
had
> a dull metal or shiny rust, both of which was unsatisfying. If one could
> control reflectivity with a grey image, one could overlay a corresponding
> image-map and hopefully achieve much better results.
>

The answer in that case would be to use a texture map instead of
layers

texture {
 bozo // or whatever
 texture_map {
  [0.0 texture {Metal}]
  [0.7 texture {Metal}]
  [0.8 texture {Rust}]
  [1.0 texture {Rust}]
 }
}

That said, I'd also like to have a finish map.

Gail
*************************************************************************
* gsh### [at] monotixcoza                *   Step into the abyss,           *
* http://www.rucus.ru.ac.za/~gail/   *   and let go.        Babylon 5   *
*************************************************************************
* The difficult we do immediately, the impossible takes a little longer *
*************************************************************************

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