POV-Ray : Newsgroups : povray.advanced-users : Focal Blur : Re: Focal Blur Server Time
3 Jul 2024 05:35:33 EDT (-0400)
  Re: Focal Blur  
From: Reactor
Date: 5 Aug 2008 23:35:00
Message: <web.48991aa93d3f48e7bf3475910@news.povray.org>
"Tim Attwood" <tim### [at] comcastnet> wrote:
> > I have already looked at it, and it does do something very similar to what
> > I
> > want, but is still on arbitrary values.
>
> The origin of a ray is perturbed semi-randomly X,Y along the "film",
> from there it passes through the focal point until it has some
> color from raytracing the scene. Aperture controls the amount of
> random displacement of the origin of the ray. Each final pixel on
> the "film" is the weighted average of the sample rays cast. At certain
> sample sizes the displacement pattern is pre-set to provide a good
> hexagonal grid, as more samples are used they are added randomly
> positioned in addition to the pre-set grids. So for example if you
> have 50 samples, 37 of the samples will be the largest pre-set
> pattern, and 13 samples will be random patterned. In general the
> pre-set patterns are weighted so that rays that are displaced farther
> from the actual pixel origin have less contribution to the final pixel
> value. That's why it's considered arbitrary, the falloff data comes
> from an array instead of a function.
> Overall it's close to being recpirocal of displacement distance.
>
> Unfortunately this means that there is no easy way to set DoF without
> accounting for differences based on samples, and general POV scales.
>
> The results are also not diminished in luminance over distance
> like with a RL camera, so far away blurred objects can look brighter.


Interesting... for some reason, I am more intrigued than anything else.  I do
think I still may be able to fake things, but this also interests me from an
improvement and development standpoint for 4.0.

-Reactor


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.