POV-Ray : Newsgroups : povray.binaries.images : Light bleeding proof-of-concept : Re: Light bleeding proof-of-concept Server Time
3 Mar 2024 17:52:18 EST (-0500)
  Re: Light bleeding proof-of-concept  
From: Samuel B 
Date: 1 Feb 2024 20:20:00
Message: <web.65bc41f31001de5316bed5696e741498@news.povray.org>
Cousin Ricky <ric### [at] yahoocom> wrote:
> My idea was to bleed only light that exceeded the RGB dynamic range;
> that is, color in excess of rgb 1.  Colors within the dynamic range
> would remain un-smeared.  My first thought was to see if I could adapt
> Sam's luminous bloom rig for this purpose, but I haven't been able to
> figure out how he did it.
>
> I settled on mathematical manipulation of a pigment function.  The
> source image was rendered in the EXR format.  It was slow, but it got
> the job done.  This POC tries to get the look of iris diffraction.
>
> bleed_test_image2.jpg is a JPEG render of the source image.  As noted
> above, the actual source image was an EXR.
>
> bleed_poc1-excess2.jpg shows the colors in excess of rgb 1.
>
> bleed_poc3-power4.jpg shows the excess color smeared out into 4
> diffraction spikes.
>
> bleed_poc4-final4.jpg is the final combined image using 10 diffraction
> spikes.

It looks good, Ricky!

My original method used either averaged pigments or averaged function
pigments... I can't remember which.

My latest released version (lb7b, I think) used averaged reflective textures
with planar normals. Each texture entry used the input image to influence the
metallic reflection of the finish. It also allowed the reflection_exponent to be
specified, which in turn allowed you to control how the glare came from bright
vs. dark areas.

If I make another version I will probably use averaged pigment functions again,
since there is less computation involved.

Sam


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