POV-Ray : Newsgroups : povray.binaries.images : Cloud City II : Re: Cloud City II Server Time
15 May 2024 16:16:32 EDT (-0400)
  Re: Cloud City II  
From: And
Date: 2 Dec 2017 10:25:00
Message: <web.5a22c4b02231f8baa0bf42e40@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
> Am 01.12.2017 um 20:42 schrieb Sven Littkowski:
> > The images still look nice. Sad only, that I self have no understanding
> > of media, I wished I could help here. Sounds like you should propose a
> > new feature inside the BETA section of this newsgroup, or expanding
> > existing features to make it possible to increase the density further.
>
> The issue isn't so much whether it is /possible/ to increase the
> density, but rather whether doing so gives /realistic results/.
>
You are correct.


> The problem is that the scattering media model is designed for cases
> where the media's density is non-uniform, but low enough that the single
> scattering contribution is dominant (i.e. a typical light ray will be
> deflected from its initial direction at most once), and the multiple
> scattering contribution (i.e. light that is deflected from its initial
> direction more than once) is negligible.
>
> Compare this to the subsurface light transport model, which is
> specifically designed for cases where the density is pretty much
> uniform, but high enough that the multiple scattering contribution is
> dominant.
>
>
> To extend the scattering media model in such a manner that it gives
> reasonably realistic results for high-density media, a monte-carlo-ish
> rendering approach would have to be used, where secondary rays would be
> shot here and there along the light's path (even recursively). Expect
> noisy results and/or high rendering times.
>
> This is in fact on my wishlist, but other stuff takes priority.

I respect you.


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