Alain <aze### [at] qwertyorg> wrote:

> phong and specular highlighting can coexist in any single finish.
> Usefull for highlight that have a sharp, bright, center area surrounded
> by a relatively dim broad and fuzzy area.
>
> The toon part should use low brilliance, possibly as low as zero. That
> make the illumination angle independant, resulting in flat textures
> typical to most toons.
>
> For most models of diffuse, you shouls take a look at the brilliance. It
> controlls the relation between the incident light angle relative to the
> normal of the surface.
>
> In POV-Ray, fresnel is a reflection component. It needs an ior to work
> (in interior), but not any transparency. If the fresnel from blender
> affect the coloration of the highlights or reflection, then you should
> use the metallic keyword.
>
> Also, take a look at the exponent and falloff for the reflection.
>
> Version 3.7 beta dependent:
> aoi pattern: depends on the direction from whitch the surface is
> observed. Takes vewing from reflection and refraction into acount.
>
>
> Alain

Thanks, all this will be very helpfull.

Blender diffuse fresnel shader is not the ior dependant raytraced reflections,
those can be set up separately too. instead, it's using an indice to vary the
diffuse shading, normal dependant with it's reference ray based on the lamp, not
on the view. Blinn on the other side is a "non raytraced specularity that
correctly computes its intensity and extension via Snell's Law." using user
input ior.

1-To emulate that in Pov, would an extreme exponent with raytraced reflection
improve rendertimes to be comparable with a non raytraced specular?

2-What's the difference between aoi and slope_map?

Here is what I have so far:
_____________________________________________________________________________
> > Blender Specular:          |Povray keywords:
_______________________________|_____________________________________________
> > Phong                      |Phong
_____________________________________________________________________________
> > Blinn                      |high brilliance, either specular or maybe use
> >                            |reflection, fresnel, very low exponent.
_____________________________________________________________________________
> > Toon                       |phong (extreme phong_size)
_____________________________________________________________________________
> > WardIso                    |Specular (and/or phong for a few values?)
                               |could access the widest range of roughness and
> >                            |brilliance
_____________________________________________________________________________
> > CookTorrence (default)     |Phong
_____________________________________________________________________________
_____________________________________________________________________________
> > Blender Diffuse:           |Povray keywords:
_____________________________________________________________________________
> > Lambert (default)          |some chosen brilliance to match blender's
_____________________________________________________________________________
> > Oren Nayar                 |Brilliance (probably between 1 and 10)
_____________________________________________________________________________
> > Toon                       |brilliance probably below 1
_____________________________________________________________________________
> > Minnaert                   |slope map(/aoi)
> > Fresnel                    |(slope map/)aoi

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