"Neil Conway" <nei### [at] yahoocom> wrote in message
news:web.3e4118dbc7b69b7a1c4fca030@news.povray.org...
> Christopher James Huff wrote:
>
> >POV is currently only capable of handling diffuse reflections of light
> >emitted by media, such as light bouncing off a sheet of paper, or media
> >seen directly. Specular reflections, like light bouncing off a mirror,
> >are not handled.
>
> I've read the FAQ's on this before, but I must admit I'm still somewhat
> puzzled.  A perfect mirror (unlike machined metal) should be trivial to
> handle - the direction of the ray is simply reflected about the normal to
> the mirror, after which you track it until it hits something else.  Is it
> that people want to handle imperfect mirrors?  Or is it simply that the
> angular density of the rays becomes an issue?
> (On re-reading your paragraph above, I realise you meant specular
> reflections of light emitted from media.  However, I understood from the
> docs that specular reflections aren't really handled at all - correct?)

Just to muddy the waters... specular reflection of light can be done in POV by
using photons (like many raytracers, POV doesn't handle specular reflection of
light easily, since rays are traced from the camera to the light source).

It sounds as though you need a combination of emitting media, radiosity and
photons - others will have to comment on whether those three components interact
properly together or not. Even if they do, it's going to be a hellishly long
trace. It does occur to me that, for a general impression, the pre-trace output
might be enough to indicate the bright and dark spots, and how they are affected
by changes to surface properties.

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