I was playing with radiosity, because it's fun :), and suddenly I 
thought of something: radiosity-effects are added to the current color 
of the pixel, radiosity can never make a pixel darker than it would be 
without radiosity.  So if you're not rendering to a HDRI, and if 
clipping is done before anti-aliasing (which, I know, isn't at the 
moment), POV-Ray could actually stop doing it's radiosity-calculations 
once a pixel has become completely white (or has become "close enough" 
to completely white).

Ok, a lot of if's there, but especially for test-renders, those if's 
shouldn't be too much of a problem, should they?

just an idea of course, and quite possibly not worth even taking the 
time to consider implementing, given that it could only help in very few 
cases, but still, maybe worth considering to be considered? :p

cu!
-- 
#macro G(b,e)b+(e-b)*C/50#end#macro _(b,e,k,l)#local C=0;#while(C<50)
sphere{G(b,e)+3*z.1pigment{rgb G(k,l)}finish{ambient 1}}#local C=C+1;
#end#end _(y-x,y,x,x+y)_(y,-x-y,x+y,y)_(-x-y,-y,y,y+z)_(-y,y,y+z,x+y)
_(0x+y.5+y/2x)_(0x-y.5+y/2x)            // ZK http://www.povplace.com

Post a reply to this message

Zeger Knaepen nous apporta ses lumieres en ce 12/04/2006 18:53:
> I was playing with radiosity, because it's fun :), and suddenly I thought of
something: radiosity-effects are added to the current color of the pixel, radiosity
can never make a pixel darker than it would be without radiosity.  So if you're not
rendering to a HDRI, and if clipping is done before anti-aliasing (which, I know,
isn't at the moment), POV-Ray could actually stop doing it's radiosity-calculations
once a pixel has become completely white (or has become "close enough" to completely
white).
> 
> Ok, a lot of if's there, but especially for test-renders, those if's shouldn't be
too much of a problem, should they?
> 
> just an idea of course, and quite possibly not worth even taking the time to
consider implementing, given that it could only help in very few cases, but still,
maybe worth considering to be considered? :p
> 
> cu!
What about some negative pigment? or negative ambient? Those can darken your
surrounding pixels.
Also, if you have a recursion_limit of more than 1, pixels whiter than white will
illuminate the 
surrounding area more than those that are "only" white.

-- 
Alain
-------------------------------------------------
I love you not because of who you are, but because
of who I am when I am with you..

Post a reply to this message

Radiosity is calculated on surfaces in 3D space, not per pixel. Since a
surface which is white from one point of view might be grey when, say,
reflected off a dull mirror (reflection .5), continuing to increase its
brightness is important.

 - Slime
 [ http://www.slimeland.com/ ]

Post a reply to this message

"Alain" <ele### [at] netscapenet> wrote in message 
news:443da863$1@news.povray.org...
> What about some negative pigment? or negative ambient? Those can 
darken your surrounding pixels.
> Also, if you have a recursion_limit of more than 1, pixels whiter than 
white will illuminate the 
> surrounding area more than those that are "only" white.

didn't think of all that :(

Post a reply to this message

Alain wrote:
...
> What about some negative pigment? or negative ambient? Those can darken 
> your surrounding pixels.
...

Radiosity scenes with negative ambient values in textures:

From: Gilles Tran
Subject: Radiosity test (60kbu)
Date: 6 Aug 2000 18:24:21
http://news.povray.org/povray.binaries.images/thread/%3C398DAC6E.810C4E7%40inapg.inra.fr%3E/

From: Gilles Tran
Subject: Radiosity test #2 70 kbu
Date: 7 Aug 2000 16:42:33
http://news.povray.org/povray.binaries.images/thread/%3C398EE60E.DCFE0C7E%40inapg.inra.fr%3E/

-- 
Tor Olav
http://subcube.com

Post a reply to this message