"Chris R" <car### [at] comcastnet> wrote:
> "Clarence1898" <dle### [at] comcastnet> wrote:
> > Cousin Ricky <ric### [at] yahoocom> wrote:
> > > On 2025-08-12 15:50 (-4), Clarence1898 wrote:
> > > > Many years ago my grandchildren loved to play with this when they came over. 
I
> > > > thought it would be fun to model it in povray.  One problem I had was the
orange
> > > > color of the arm was not bright enough.  I could never get it bright enough
> > > > until I learned you could specify color values greater than one.  Using
> > > > rgb<2.0,0.5,0.0> finally matched the real object.
> > >
> > > Assuming you haven't changed the default finish diffuse, this works out
> > > to a final color of rgb <1.2, 0.3, 0.0>.  Counterintuitively, I have
> > > found that this color is quite physically possible in the real world,
> > > given the limitations of the sRGB color system used by most computer
> > > screens.
> > >
> > > The image spectral_orange.png shows some spectral power distributions
> > > for oranges and adjacent colors.  As you can see from the negative
> > > channel values, all of these colors are too saturated to be shown
> > > accurately on a standard computer screen; what you're seeing is a
> > > desaturated approximation. But relevantly, all but the first and last
> > > colors have red values greater than one, even though they never reflect
> > > more light than they receive at any wavelength.  As a result, POV-Ray
> > > clips the red values.
> > >
> > > The image spectral_orange-gld.png uses UberPOV to show the true
> > > luminance of the oranges, but at the expense of saturation.  Within the
> > > limitations of the sRGB color system, something has to give.
> > >
> > > I would just be careful not to do this with metallic reflection, as that
> > > can cause problems.  With metallic reflection, you really would be
> > > reflecting more light than you receive.
> >
> > This is the texture I used:
> >
> > #declare tPlasticOrange =
> >   texture {
> >     pigment{rgb <2.000, 0.50, 0.0>}
> >     finish {
> >       ambient 0.1
> >       diffuse 0.6
> >       specular 0.3
> >       }
> >     }
> >
> > It was derived by pure trial and error.  Until I increased the red value above 1
> > I couldn't get the color bright enough to match the real object.  I took a
> > picture of the object and adjusted the color and finish until it matched.  I
> > will keep in mind not to do that with metals.  Though now I am tempted to try it
> > just to see what happens.
>
> Very cool!  I, too, like creating models of toys and have several scenes with
> older ones.
>
> Did you use image-maps for the labels?
>
> Another thing to try with the textures would be to use fresnel reflection in the
> finish.
> -- Chris R

Yes, I scanned the labels and used them for an image_map.  I have never used
fresnel reflection, will have to try it.  I enjoy modeling interesting things.
I didn't have povray when my kids were little,  but enjoyed doing the toys my
grandkids had.  Now that they are grown I don't have any toys to model anymore.

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