[sldev] Google Summer of Code 2008 update

[Eric M. Tulla (BigPapi Linden)]

Argent Stonecutter wrote:
> On 2008-05-01, at 13:20, Eric M. Tulla (BigPapi Linden) wrote:
>> There is no good way to do that as a half measure.  If you don't
>> calculate shadowing in general, you would get horrible flickering of the
>> entire scene any time *anything* gets between your avatar and the sun,
>> such as a lamp post or a tree.
> That's an obvious problem, with an obvious solution, which is to base 
> the "indoors" versus "outdoors" view on a tunable "X% of the sky 
> within Y% of the sun is hidden". This has already been discussed in 
> the Jira.
Yes, that is an "obvious" solution, but that doesn't mean it's a 
computationally simple one.  Abstractly knowing the percent of the sky 
that is hidden even within some smaller angle of the sun is easy for the 
human brain to know at a glance, but not even remotely easy to do within 
the context of 3d rendering.  The complexity of calculating that on the 
fly would be similar to or worse than just calculating proper shadowing, 
which is what we're working on.  This is one of those rare cases where 
the better looking solution can be made to run faster than other 
theoretically simpler but uglier solutions.

-- 
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"Quidquid latine dictum sit, altum sonatur."
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Eric M. Tulla
tulla at lindenlab.com
Graphics Programmer
Linden Lab