>> 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?
> I don't think so.
> Blinn seems to emulate or fake fresnel based variable reflection.
>>
>> 2-What's the difference between aoi and slope_map?
>>
>
> Those two are similar in implementation but differs as follow:
>
> slope depends on the orientation of a surface relative to an arbitrary,
> user defined, direction. If you move the camera, the resulting pattern
> will never change. If you view the same object directly and it's
> reflection, there is no change to the pattern.
> Typicaly, the values can range from 0 to 1. There is an optional
> altitude component that allow the texture to change acording to the
> "altitude" as well as it's local slope.
> In your case, it could be the lamp-object vector.
> If you need it to take more than one light_source, you'll need to layer
> several pattern using partialy transparent pigments, one per light_source.
>
> aoi depends on the orientation of a surface relative to the direction at
> whitch it is observed. If you move the camera, the resulting pattern
> will always change acording to the new location. Typical values range
> from 0 to 0.5. The 0.5 to 1 range belong to the part that's facing away
> from the point of view and normaly not visible unless the normal gets
> disturbed.
> aoi is not available in version 3.6 and earlier. There is a version of
> that pattern implemented in megapov, but it don't function the same way.
> ____________________________________________________________________
>  >>>> Toon |brilliance probably below 1
> Change that to: brilliance under 0.25, probably closer to 0
>
> Make some tests using a box and a plain sphere using a bland white pigment.
>
>
>
> Alain
Also, for the toon part:
You may also look for a finish with a low diffuse value and a high 
ambient value.

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