Hello Alain,

thank you for the hints. I will study the mentioned sample files. If I  

have further questions, I will come back to here.

Herbert





Am 13.11.2010, 02:11 Uhr, schrieb Alain <aze### [at] qwertyorg>:


>> Hello,
>>
>> I want to deal with light diffraction using photons. In the PovRay
>> manual chapter 3.6.3.1.1 there are shown
>> two examples. Where can I find the related source code?
>>
>>
>
> POV-Ray support reflection and refraction. Refraction also support  

> chromatic dispersion.
>
> Diffraction is NOT supported as it depends on waves interference and  

> there is no light waves in the model used.
>
> You should continue your reading for the following sections: 3.6.3.2 t
o  

> 3.6.4
>
> There is no diffraction in either of those scenes. There is also NO  

> dispersion.
> The first image show only a single white light_source.
> The second one DON'T actualy use dispersion but fake it using 3  

> light_sources, one red, one green and one blue.
>
> To my knowlege, the POV files for those scenes are not included with t
he  

> distribution.
>
> The following sample files use photons and are included in the  

> distribution. They can be found in the advanced folder:
> diffract.pov
> newdiffract.pov
> optics.pov
> grenadine.pov
>
> NONE of those show any diffraction.
>
> What is important to know:
> 1 - You must turn photons ON in the global_settings, and specify ether
  

> the total number of photons (count) to shoot OR the density of the  

> photons (spacing). There are other oprional parameters.
>
> 2 - The objects that are meant to interact with the photons need a  

> photons block to set them as target and enable reflection or refractio
n.
>
> 3 - You don't need any photons block for the light_source. ALL  

> light_source without "shadowless" automaticaly shoot photons whenever 
 

> photons are enabeled.
>   - shadowless light_source NEVER shoot any protons. They also never  

> cause any highlight.
>
> 4 - For ANY transparent object that have an ior and dispersion set to 
a  

> value different than 1 AND zero, the dispersion will affect photons.  

> There is nothing else to add.
>
> Thin film interference CAN be simulated using irid in the finish.
>
>
>
> Alain


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