nemesis <nam### [at] gmailcom> wrote:
> It seems this feature, while a nice optimization trick, is what prevents one
> from reusing a full saved rad file to render a file from a different angle
> without taking any more samples and probably also the root cause of not being
> able to simply break an image into sections, render them separately and simply
> merge the final renders into a single image later.  Each instance do not know
> they should be taking samples from areas not seen in their particular view.

  I don't see how viewpoint-independence would help solve the problem. The
only thing a viewpoint-independent solution would do is calculate more
samples (including many samples which do not contribute anything to the
rendered image) and that's it. It might allow re-rendering the scene with
a moved camera without having to calculate more samples, but I don't see
how it would help any of the actual problems.

  A viewpoint-independent version of the current algorithm would (most
probably) not reduce lighting artifacts, make it any easier to get
good-looking lighting without tons of tweaking, and most relevantly,
would not make it any easier to distribute the calculation of the samples
at render-time. You would still have all the problems of the current
algorithm (eg. how to make one thread see the results of another, how
to avoid two threads calculating the same sample, etc).

> Perhaps this optimization was powerful then, but not quite as fitting in an era
> of multicore processors and parallel processing.

  The global illumination algorithm used by POV-Ray was slow then, and it's
slow nowadays. Deliberately making it even slower is not the way to go.

-- 
                                                          - Warp

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