"JSR" <jsr### [at] gmailcom> wrote:
> Hello,
> I'm new to this newsgroup. I'm very interested in learning indoor lighting
> and rendering using lights and radiosity. I have been working with POV for
> a long, but I can't render images with impressive lighting like these:
> http://www.pacificommultimedia.com/architecture.html
> http://www.artvps.com/gallery/1/architecture.htm
>
> At the moment, the best image I rendered is this. I think that it is not
> very bad, but seems a little dark. If the brightness parameter is
> incremented then the image is burn.
> Suggestions are well received.
> Thanks,
>
> jsr.

I have to say I like your image a lot, but perhaps you didn't want light
from an overcast day?

I don't have any direct experience, but some of my favorite POV interiors
are by Jaime Vives Piqueres, like the ones here:
http://www.ignorancia.org/en/index.php?page=Modern_interior
Especially this one:
http://www.ignorancia.org/uploads/images/modern_interior/wips/interior2-060819-1.jpg

I think Jaime manages to get bright daylight without the image blooming and
losing color definition. My (limited) understanding is that for the lights
in some images he uses several sources: large area_lights on each
window/outside door, to simulate the diffuse light from the sky and
environment, and one brighter light at the sun-position for the actual
sunshadows. This gives better results than the pure sunlight+radiosity that
is perhaps closer to reality, IMO. Of course he also gets good fading
distance and light values from his LightsysIV light simulation system.

(If any of this is wrong, sorry, some is just speculation.)

Good luck- you have a nice interior to experiment with!

-Stefan Sittler

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Alain wrote:
> JSR nous apporta ses lumieres en ce 24/10/2006 17:37:
>> Thanks to all for your fast repost,
>> The color light I use for the image is <0.75, 0.72, 0.53>, it's to
>> say, yellowish white. The idea was to represent a sunset and I use
>> this color because it's the recomended by Jeremy Birn in his "color
>> table": http://www.3drender.com/glossary/colortemp.htm
>>
>> I think that this image...
>> http://www.nolights.de/stills/gallery/images/prep4company.jpg
>> ..... is very beautiful and lighting is very realistic, I would like
>> to see the source pov code of this image in order to have an idea of
>> what was wrong in my image, comparing the materials, lights,
>> radiosity,... JSR
>>
> Your "sun" may not be bright enough. Try multiplying it's value by
> something around 1.5 to 2. This won't change the colour.
> The shadow of the window looks to sharp, I'd use an area_light.

Indeed, I found the key is to get the ratio of brightness between the sun 
light and the sky colour correct.  You can look at photos of similar scenes 
to make an estimate.  Make sure your gamma settings are correct.  If you 
want your indoor scene to be well exposed then both the sun and sky colour 
will likely need to be above <1,1,1>.

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"JSR" <jsr### [at] gmailcom> wrote:
> Thanks to all for your fast repost,
> The color light I use for the image is <0.75, 0.72, 0.53>, it's to say,
> yellowish white. The idea was to represent a sunset and I use this color
> because it's the recomended by Jeremy Birn in his "color table":
> http://www.3drender.com/glossary/colortemp.htm
>
> I think that this image...
> http://www.nolights.de/stills/gallery/images/prep4company.jpg
> ..... is very beautiful and lighting is very realistic, I would like to see
> the source pov code of this image in order to have an idea of what was
> wrong in my image, comparing the materials, lights, radiosity,...
>
> JSR

Sure, I'm at the university right now, but when I get back home, I'll see
what I can do. The chair and sofa are big meshes though, so I guess I'd
have to take those out of the scene-file and replace them with something
simpler (low-res, probably), but you'll get the materials and lighting.

Regards,
Tim

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Smws wrote:
  > I have to say I like your image a lot,

   Me too! I think JSR managed to get a very good lighting here (apart 
from a very nice room and furniture), but some more intensity on the 
sunlight will help further.

> I think Jaime manages to get bright daylight without the image blooming and
> losing color definition. My (limited) understanding is that for the lights
> in some images he uses several sources: large area_lights on each
> window/outside door, to simulate the diffuse light from the sky and
> environment, and one brighter light at the sun-position for the actual
> sunshadows. This gives better results than the pure sunlight+radiosity that
> is perhaps closer to reality, IMO. Of course he also gets good fading
> distance and light values from his LightsysIV light simulation system.

   Actually, this images uses another alternative to the "realistic" 
sunlight+rad approach: ambient boxes in place of the window glasses, 
with coloring dependent on the sky color from skylight.inc. So it's 
still sunlight+rad, but helped a bit with these emitting surfaces and a 
recursion level of 2. When using two-pass rad, you can put back the real 
glass for the final render.

> (If any of this is wrong, sorry, some is just speculation.)

   No, you are right: I really used area lights on the first images... 
but it was too slow for my patience.

--
Jaime

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Tim Nikias wrote:
>> I think that this image...
>> http://www.nolights.de/stills/gallery/images/prep4company.jpg
>> ..... is very beautiful and lighting is very realistic, I would like to see
>> the source pov code of this image in order to have an idea of what was
>> wrong in my image, comparing the materials, lights, radiosity,...
> 
> Sure, I'm at the university right now, but when I get back home, I'll see
> what I can do. The chair and sofa are big meshes though, so I guess I'd
> have to take those out of the scene-file and replace them with something
> simpler (low-res, probably), but you'll get the materials and lighting.

I've just uploaded the ZIP with a slightly stripped down version of the 
meshes and textures to povray.binaries.scene-files. Feel free to explore 
and experiment with the settings. :-)

Regards,
Tim

-- 
aka "Tim Nikias"
Homepage: <http://www.nolights.de>

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Hi,
This image has take too long to render because of the high resolution, I
tried to improve the definition of the objects and antialias, at the same
time, I try to add bright to the scene changing the key light with
<1,1,1>*3 and sky sphere <1,1,1>.
But, in order to reduce render time I changed the count to 300, and this has
produced blotchy surfaces.
The question is: It's possible to solve this problem without a count higher
than 300 (to don't increase render time)? Changing the rest of the
parameters of radiosity? (rest are default values in this image)
Thks,

JSR

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Attachments:
Download 'indoor.jpg' (323 KB)

Preview of image 'indoor.jpg'

"JSR" <jsr### [at] gmailcom> wrote:
> But, in order to reduce render time I changed the count to 300, and this has
> produced blotchy surfaces.
> The question is: It's possible to solve this problem without a count higher
> than 300 (to don't increase render time)? Changing the rest of the
> parameters of radiosity? (rest are default values in this image)

Reduce pretrace_end to 0.01 or 0.005.  That tends to mitigate the
splotchiness caused by the low error_bound.

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"JSR" <jsr### [at] gmailcom> wrote in message
news:web.453f8a843cae5eb8d8ef73430@news.povray.org...
> Hi,
> This image has take too long to render because of the high resolution, I
> tried to improve the definition of the objects and antialias, at the same
> time, I try to add bright to the scene changing the key light with
> <1,1,1>*3 and sky sphere <1,1,1>.
> But, in order to reduce render time I changed the count to 300, and this
has
> produced blotchy surfaces.
> The question is: It's possible to solve this problem without a count
higher
> than 300 (to don't increase render time)? Changing the rest of the
> parameters of radiosity? (rest are default values in this image)
> Thks,
>
> JSR

just another quick thought. a room painted grey will always look gray, no
matter how nice the sunlight is coming in. find some nice paint samples and
borrow their colors :)

the room does look brighter now, anyway.

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JSR nous apporta ses lumieres en ce 25/10/2006 12:02:
> Hi,
> This image has take too long to render because of the high resolution, I
> tried to improve the definition of the objects and antialias, at the same
> time, I try to add bright to the scene changing the key light with
> <1,1,1>*3 and sky sphere <1,1,1>.
> But, in order to reduce render time I changed the count to 300, and this has
> produced blotchy surfaces.
> The question is: It's possible to solve this problem without a count higher
> than 300 (to don't increase render time)? Changing the rest of the
> parameters of radiosity? (rest are default values in this image)
> Thks,
> 
> JSR
> 
> 
> ------------------------------------------------------------------------
> 
A low error_bound needs a high count to prevent blotchness. Try to increase 
error_bound, maybe as high as 1. This will also decrease the render time.
You can compensate by using a smaller low_error_factor to get more sampling 
during the last pretrace step. Also, adding 1 or pretrace steps can help.
Increasing nearest_count up to 20 (the maximum) can also help by averaging more 
value to get the final illumination.

-- 
Alain
-------------------------------------------------
WARNING: The consumption of alcohol is a major factor in dancing like a retard.

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"JSR" <jsr### [at] gmailcom> wrote:
> Hello,
> I'm new to this newsgroup. I'm very interested in learning indoor lighting
> and rendering using lights and radiosity. I have been working with POV for
> a long, but I can't render images with impressive lighting like these:
> http://www.pacificommultimedia.com/architecture.html
> http://www.artvps.com/gallery/1/architecture.htm
>
> At the moment, the best image I rendered is this. I think that it is not
> very bad, but seems a little dark. If the brightness parameter is
> incremented then the image is burn.
> Suggestions are well received.
> Thanks,
>
> jsr.

Nice room!  One thing I noticed... the shadows are only possible with a
single point of light.  But a window is not a single point.  Rendering the
shadows correctly is very difficult (difficult on the computer).

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