"LanuHum" <Lan### [at] yandexru> wrote:

> Due to the problem of media scattering with photons there is a new question.
> From a floor on a wall light which color is reflected is set by the reflection
> parameter, but really the floor can have multi-color reflection which as I
> understood, it is impossible to set.


Maybe I misunderstood your question, because I don't see what "the problem of
media scattering with photons" exactly is. if there is some  well known issue, I
haven't come across it yet, could you explain more in detail what is wrong with
media or photons? Otherwise, if you just want "colored reflections" these could
be of three form:
*realistic diffuse reflection(radiosity)
*specular (phong or specular keyword in pov)
*raytraced mirrored "image" of reflected objects (reflection keyword in pov)

In the case of the first pov feature type (radiosity) local colors will be
transfered to reflective surface automatically.

For both the second and third types, you can set custom colored reflection. the
color of those will then depend more on the reflective objects color than on the
reflected ones. We set those  with the "metallic" keyword in the respective
blocs.

This is already implemented in the official version of the blender exporter. it
has given me a hard time and brought a few bugs along that I (or anyone willing
to help if there ever is one) still have to fix, like the multiple materials per
object that got broken, mostly because objects and materials that first get
created are not given a declared name consistently yet.

The hardest thing to implement was to allow the use of a specular color
different from the diffuse color while maintaining as many textured bitmaps as
possible: alpha, bump and diffuse: specular mapping wich is the last one
available for the usual case of a non colored specular highlight of potentially
unequal intensities in various points of the surface, this had to be disabled
since custom colored specularity uses layered textures:
the upper layer has metallic keyword to give specularity the color of an
invisible pigmentwith full transmit, taken from the Blender "specular_color"
field.
And it happens that patterned textures aka the "finish map" technique used for
modulating finish specular intensities across surface according to a bitmap)
can't be used within layered textures.

this is a known POV-Ray limitation. All other solutions offered so far involve
breaking some existing exporter feature such as multi material per object
(indeed currently broken but fixable).

I wish the best to your exporter and I hope to be able to take things from it
soon and give you credit for them.

Take care and enjoy.

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