"JC (Exether)" <no### [at] spamfr> wrote in message
news:407afbfa@news.povray.org...
> IMBJR wrote:
>
> > "JC (Exether)" <no### [at] spamfr> wrote in message
> > news:407ac7f4$1@news.povray.org...
> >
> >>IMBJR wrote:
> >>
> >>>3-light system used, probably incorrectly tho.
> >>
> >>Not so bad. :-)
> >>For some reason, the position for the back light that is given in
> >>tutorials does not quite work in my scenes, it seems I'm not the only


> >>lit areas that will let you see the shape of your spheres better.
> >
> >
> > If I understand correctly, the angular relationship between the key and
> > backlight is already at 135 degrees (viewed down the y-axis), since the
key
> > light is 45 degrees off  to the left and the backlight is behind the
> > subject. It might help if I position the lights by putting them at a
> > standard position and rotating them around the subject instead of my
rather
> > rough positioning by offsets.
>

> with the >camera<, you should turn it around so that it lights the right
> part of the object. It would be easier working with angles, but you can
> set it up with offsets too. I posted the source of the menger sponge in
> p.t.scene-files on 18/08/2003 if you want to have a look at the 3 lights
> code.

http://www.mavart.com/art-film-three-point.html
is just one of a number of sites that give yet another slight variation in
the rules.
This one agrees with my original interpretation that the back light is 180
degrees to the camera, behind the subject.

>
> >>Try to render your image with only one of the three lights (trying with
> >>key, fill and back) and you'll see better what happens and which brings
> >>what.
> > The key light is certainly key. I've set it up so I have a test render
of
> > the target object available, and the other 2 lights provide little
light,
> > but more than the recommended light mind - I thought that they needed
more
> > of a presence.
>
> Back light should provide as much light as the key light, because it's
> in the back it won't provide too much light.

The site above indicates a smaller light (than the key light) is to be used.

Blimey. Well I suppose it's not a bad thing not to lay down hard and fast
rules for first-time lighting technicians etc.

>
> >>How many spheres do you have in this render ?
> > Durn, you've made me re-parse this monster to find out: There are ...
mmm,
> > POV-Ray does not say how many blob components there are!
>
> Sorry, I was just beeing curious as your algorithm provides a lot of
> spheres for the outside, but fewer for the inside, so I thought the
> result might be interesting. You can use #debug traces to know.

I think that's probably for the future. I'm gurding up my parts to work on
something that can produce DXF output.

>
> JC
>
> -- 
> http://exether.free.fr/irtc (more IRTC stats !)

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