Alain <ele### [at] netscapenet> wrote:
> This is not realy a "beginner" thing.
>
> You can try it several ways.
> You can use some layered textures, each one including it's own finish.
> You can use several copies of the same object, varying the size by a very small
> amount. The outside one been mostly transparent, with some iridescence and
> slight reflection. This require a fairly large max_trace_level an will get
> relatively slow to realy slow.
>
> To my knowlege, there are currently no macro or function to that purpose.
>
> irid simulate a single film. The model is fairly simple and easy to implement.
>
> Multiple films are another story. The end effect depends on the respective ior
> of each layer, the order of the iors, as well as ther thickness. Not all layers
> have the same thickness. The total number of layers can change.
> Was the purpose of the multilayers to suppress reflection, or enhance it? For
> just a few wavelength, or a broad spectrum?
>
>
> --
> Alain
> -------------------------------------------------
> Why do psychics have to ask you for your name?

Thank you very much for your answer! I am not sure how I could use layered
textures. I am guessing I would just have to divide the bowl into zones and
have the zones colored differently? Otherwise how would layering the textures
change the angle dependence? Or do you think I could actually put down many
layers with different refractive indexes and thicknesses and turn photons on?
Will POVRay actually end up calculating interference colors in this case?

Yes, that is exactly right about the multilayers. I have used free software
FreeSnell (http://people.csail.mit.edu/jaffer/FreeSnell/) to calculate the
spectra at different angles and then calculated the RGB values from there.
Would it be possible to enter a table for BRDF RGB values somewhere and
designate a finish to use that BRDF from a look-up table?

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