Warp <war### [at] tagpovrayorg> wrote:
> C. Cappai <nomail@nomail> wrote:
> > Full area light!
>
>   Perhaps "full" was not a wise choice of word, as it can be slightly
> misleading. My original intention was for it to mean "everything
> related to rendering the effects of light sources, that is, shadows and
> diffuse/specular lighting, can now take into account the area light
> parameters". (Previously only shadows took into account area light
> settings.)
>
>   I understand now that someone could perhaps mistakenly think that
> "full" means area lights are now simulated as true area lights, ie.
> lights with a non-zero surface area, instead of an (optimized) grid
> of point lights.
>
>   That's of course not the case. Area lights are still a grid of point
> lights, which are (smartly) sampled. The difference is that the sampling
> can now be turned on for diffuse/specular lighting too. This means that
> the Size_1 and Size_2 still determine the quality (and rendering speed)
> of the result. You can still get the same artifacts (and now with the
> illumination too) if you specify parameters which are too low.
>
>   (I don't mean to say that I think you misunderstood this. I just wanted
> to post a note about this, and this felt like a good place to do it.)
>
>   Note that 'adaptive' has no effect on the illumination, only in the
> shadows, as previously. This is because there's no easy way to adaptively
> sample the illumination, as it is with shadowing. 'adaptive' should,
> naturally, still be used for faster rendering because it still speeds
> up shadow calculations a lot.
>
>   Basically the end result, when using area_illumination, should be
> almost exactly the same as when using a true grid of point lights,
> except that it should render considerably faster. (This is because
> shadow tests will be much faster.)
>
>   IIRC the 'area_illumination' keyword was suggested by Gilles, and it's
> IMO a superb keyword, as it's much more unambiguous than anything containing
> the word "full" in it.
>
> --
>                                                           - Warp

Explanation extremely useful.

Thanks for your work, Warp.

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