"Nathan Kopp" <nat### [at] koppcom> wrote...
>
> "Patrick Dugan" <pat### [at] usnetcomcorpcom> wrote...
> >  The docs seem
> > to indicate "field_depth specifies the length of the focal range.  All
> > objects within the range of (field_start) to (field_start+field_depth)
> will
> > be fully in focus. " to me means objects close to the camera would also
> > become blurry when they are out of the range.  Testing shows this is not
> > true.
>
> It USED to work.  Really, it did!  I remember testing it.  It actually
uses
> two different algorithms (both ad-hoc, neither based in reality) for
> camera->field_start and field_end->infinity.

Ok... here's the problem.  The ad-hoc algorithm from camera->field_start is
bad.  Oh, well.  Sorry.  I just made it up one night (probably at 1 in the
morning) and it looked cool for the scenes that I tested it in, so I kept
it.

The whole focal_blur filter was supposed to be a proof-of-concept anyway.  I
didn't do any research on algorithms before (or even after) I started
working.

Change the field_start value to 20 to see what I mean - you DO get bluring
before field_start.  It's just so minimal that you don't notice it unless
you move field_start far away.

-Nathan

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