kas### [at] gmxde news:416b8296@news.povray.org

> recursion_limit 2 brightness 3.0}

Uhm, I'm afraid ushc settings are totaly psychical incorrect - surfaces 
diffuse up to x3 times more light then their get.

If You would set higher quality (i.e. recursion_limit 5) probably entire 
scene will be totaly white / overlighted, since walls will recive about
3*3*3*3*3 * 1 RGB light

-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics

Post a reply to this message

Rafal 'Raf256' Maj wrote:

>>recursion_limit 2 brightness 3.0}
> 
> 
> Uhm, I'm afraid ushc settings are totaly psychical incorrect - surfaces 
> diffuse up to x3 times more light then their get.

Remember that Pov-RAY tries not to simulate reality but to produce 
(photo)realistic images. There are many limitations that might cause one 
to use higher brightness than 1. For example, sometimes it is not 
feasible to set the lightsource ambient value more than 1 as it might 
get clipped. Then the only way to get enough illumination is to increase 
brightness value. Megapov's exposure setting might help with this - 
haven't tried it though.

This is all about getting the desired result, not about actual values 
being used. You are seriously limiting yourself by allways using just 
brightness 1 (and fade_power 2 etc.).

> If You would set higher quality (i.e. recursion_limit 5) probably entire 
> scene will be totaly white / overlighted, since walls will recive about
> 3*3*3*3*3 * 1 RGB light

It all depends. Usually increasing the recursion limit beyond a certain 
value doesn't affect the result almost at all. When diffuse 
inter-reflections are calculated, the intensity gets smaller and smaller 
at every iteration (depending on the surface color, diffuse, ambient 
etc. values) and finally has no influence on total radiosity value. I 
think there aren't many "normal" scenes that look practically any 
different with recursion_limit 10 or 20.

Severi

Post a reply to this message

"Rafal 'Raf256' Maj" <spa### [at] raf256com> wrote:
> kas### [at] gmxde news:416b8296@news.povray.org
>
> > recursion_limit 2 brightness 3.0}
>
> Uhm, I'm afraid ushc settings are totaly psychical incorrect - surfaces
> diffuse up to x3 times more light then their get.

Even as ray tracing is a pretty snappy algorithm and POV-Ray does it very
well indeed, it seems to me (from my own experience and the works of
others) that the best results often are obtained with a little bit of
'un-physical' modelling.  There are so many approximations that have do be
done that this is not really surprising either.  For example, see this post
for a convincing example:

http://news.povray.org/415b0865%40news.povray.org

In my rad room I stil have recursion_limit > 5 (I plan to decrease though)
with brightness in the 2+ range.  Unphysical?  Could be, but I get the
pictures I want.

--
jussi.kantola

Post a reply to this message

>> recursion_limit 2 brightness 3.0}
>
> Uhm, I'm afraid ushc settings are totaly psychical incorrect - surfaces
> diffuse up to x3 times more light then their get.
>
> If You would set higher quality (i.e. recursion_limit 5) probably entire
> scene will be totaly white / overlighted, since walls will recive about
> 3*3*3*3*3 * 1 RGB light

If I want my 4 spotlights to light the entire room, without overexposing the
places they point at, I have no choice but to reduce light intensity and to
increase radiosity brighness. Or have I? I do not plan to use higher
recursion_limits, it will slow down the whole thing to much. For the final
renders I'll choose :

radiosity { Rad_Settings(Radiosity_Final, off, off) recursion_limit 2 brightness 3.0}

The lighting is how I want it to be, and Radiosity_Final will make sure that no
artifacts are left...

Manuel

Post a reply to this message

kas### [at] gmxde news:416bd648@news.povray.org

> t 2 brightness 3.0}
>>
>> Uhm, I'm afraid ushc settings are totaly psychical incorrect -
>> surfaces diffuse up to x3 times more light then their get.
>>
>> If You would set higher quality (i.e. recursion_limit 5) probably
>> entire scene will be totaly white / overlighted, since walls will
>> recive about 3*3*3*3*3 * 1 RGB light
> 
> If I want my 4 spotlights to light the entire room, without
> overexposing the places they point at, I have no choice but to reduce
> light intensity and to increase radiosity brighness. Or have I?

I think that increasng light intensity _and_ using 
light_exposure should give good efect, it is what it's designed for AFAIK 
;)

-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics

Post a reply to this message

OMG, please stop posting photographs!

But seriously, this is darn cool! The only thing I don't like is that 
pure white interior of the lamp facing the camera. Either put a light 
bulb in there, or something else, lens-flares (don't think it would look 
good) or scattering media in the whole room, so that it's not simply a 
white lamp-interior, but a beam of light.

Florian
-- 
camera{look_at-y*10location<8,-3,-8>*10}#local a=0;#while(a<999)sphere{
#local _=.01*a-4.99;#local p=a*.01-5;#local c=.01*a-4.995;<sin(p*pi)*5p
*10pow(p,5)*.01>sin(c*c*c*.1)+1pigment{rgb 3}}#local a=a+1;#end
/******** http://www.torfbold.com ******** http://www.imp.org ********/

Post a reply to this message

> But seriously, this is darn cool! The only thing I don't like is that
> pure white interior of the lamp facing the camera. Either put a light
> bulb in there, or something else, lens-flares (don't think it would look
> good) or scattering media in the whole room, so that it's not simply a
> white lamp-interior, but a beam of light.

The light bulb might actually be there but you can't see it as everything is
totally white. Megapov's exposure feature might help to get it visible.

Severi

Post a reply to this message

> OMG, please stop posting photographs!

Thank you!

> But seriously, this is darn cool! The only thing I don't like is that pure white
interior of the lamp facing the camera. Either 
> put a light bulb in there, or something else, lens-flares (don't think it would look
good) or scattering media in the whole room, 
> so that it's not simply a white lamp-interior, but a beam of light.

Yes, I know what you mean. However, the lamp wasn't meant to be
the scene, it was meant to be part of a much bigger scene. If it were
just for the lamp, I'd agree with you. To see a very WIP of my scene,
look at:

http://home.arcor.de/mad_onion/002%20rund%20-%20lighting.jpg

It's an ultra-wide-angle camera in order to make all the walls visible.

Manuel

Post a reply to this message

>> If I want my 4 spotlights to light the entire room, without
>> overexposing the places they point at, I have no choice but to reduce
>> light intensity and to increase radiosity brighness. Or have I?
>
> I think that increasng light intensity _and_ using
> light_exposure should give good efect, it is what it's designed for AFAIK

OK, maybe you're right. But as long as I can achieve what I want in pure POV3.6.1 I'll
stick to that.

Manuel

Post a reply to this message

Another lamp, from
http://www.rubygarden.org/ruby?FractalLifeEngine/LampTutorial

In retrospect, I think I picked the deep red to fit that site's "Ruby"
theme.

-- 
  Phlip
  http://industrialxp.org/community/bin/view/Main/TestFirstUserInterfaces

Post a reply to this message

Attachments:
Download 'treeLampDetail[1].png' (466 KB)

Preview of image 'treeLampDetail[1].png'