[Radiance-general] Depth-of-field hack

[Peter Apian-Bennewitz]

Hi Mark

>...
>
>I first tried pdfblur, which outputs a series of views, each
>of which can be rendered with rpict or created with pinterp.
>  
>
I'm not quite sure I see the light here yet, but I'm interested, as 
rshow had some experimental features of generating the views (actually 
before realizing there are some cmdline tools buried deeply somewhere), 
that's how the lower image at 
http://www.pab-opto.de/radiance/render_vergleich/intro.htx was rendered 
with 16 single views.

Before decompiling the rcalc script, could you briefly say why your 
method is faster ?

To give a hint of the little bits I do understand: Out-of-focus pixels 
average over a larger solid angle as in-focus ones. Even the solid-angle 
of in-focus pixels is truly not zero, that's why we need oversampling to 
avoid aliasing. Traditional methods calculate anti-aliased images with 
shifted view points and directions which are than added to give the 
blurred final result. Do I understand correctly that your method 
incorporates the depth-of-field information into the per-pixel averaging 
over the per-pixel-solid-angle ? Speed advantage would than come by 
avoiding unnecessary rays. Is there an easy way to understand how ?
With the old method, each of the images has the same size, so one pixel 
is effectively oversampled by the number of images. Whether in-focus or 
not. Are you saying that the out-of-focus ones need more sampling than 
the in-focus ones ? And the in-focus don't gain much from the higher 
sampling ?

TIA
Peter

PS: nice Radiance webpages of yours

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 pab-opto, Freiburg, Germany, http://www.pab-opto.de
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