"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

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