RE: [Algorithms] occluded light flaring

[Simon O'C. <si...@cr...>]

1) The dangers of posting in HTML - all I got was "hi", and the rest of your
message was black text on a black background. See previous discussion in
archives for many reasons why people prefer plain text on this list...

2) Modern (PC) hardware (and APIs) support asynchronous occlusion queries
where "x amount of time" after your occlusion test point was rendered,
you'll be told if it was occluded by other pixels.

3) An alternative is to render just the Z buffer of the scene around where
the test point is to a small texture, then render your test point as a white
dot (say 2x2). You then stretch that texture and modulate with the flare.
IIRC there's a full paper and/or sample code describing the technique on
either the nVidia or ATI site.


Simon O'Connor
Creative Asylum Limited
www.creative-asylum.com 

-----Original Message-----
From: andrew [mailto:an...@aw...]
Sent: 25 April 2003 13:05
To: gda...@li...
Subject: [Algorithms] occluded light flaring


hi,
 
In a lot of games when trees or buildings partially occlude the sun they
adjust the 'flare' factor of the light..I was wondering how they know to do
this? I can think of a ray cast solution..but there must be better ways...
 
andrew