I started a experiment to fake the "HDRI look", and found a simple and 
nice-looking way to do "image_map lighting" with only one radiosity level.

The trick consists on two concentric spheres, the outern one for rad 
lighting, and the inner one for reflection. The exterior sphere uses a 
gray pigment function of the image_map, with high poly_wave and and high 
ambient.

More tests here:

http://ignorancia.org/images/tests/jarron-9a.jpg
http://ignorancia.org/images/tests/jarron-9b.jpg
http://ignorancia.org/images/tests/jarron-9d.jpg
http://ignorancia.org/images/tests/jarron-11a.jpg
http://ignorancia.org/images/tests/jarron-11b.jpg
http://ignorancia.org/images/tests/jarron-11c.jpg

Some of them use suitable spherical photos found on the net, others use 
my own prior scenes rendered with spherical camera.

I will make a macro and post it later.

Regards...

--
Jaime

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Attachments:
Download 'jarron-11d.jpg' (32 KB)

Preview of image 'jarron-11d.jpg'

Quite smart idea!!!
Thank you, it is a major innovation: HDR maps are rare and usually low
resolution

Marc

de news: 405b4350@news.povray.org...
> I started a experiment to fake the "HDRI look", and found a simple and
> nice-looking way to do "image_map lighting" with only one radiosity level.
>

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Wow... I think you faked the HDRI-look very well. I didn't understand your
trick very well, as I'm not very familiar with advanced techniques like the
ones you describe, but, as always, it's a pleasure to look at your work.

Saludos,

Fernando



news:405b4350@news.povray.org...
> I started a experiment to fake the "HDRI look", and found a simple and
> nice-looking way to do "image_map lighting" with only one radiosity level.
>
> The trick consists on two concentric spheres, the outern one for rad
> lighting, and the inner one for reflection. The exterior sphere uses a
> gray pigment function of the image_map, with high poly_wave and and high
> ambient.

Post a reply to this message

Jaime Vives Piqueres wrote:
> I started a experiment to fake the "HDRI look", and found a simple and 
> nice-looking way to do "image_map lighting" with only one radiosity level.
> 
> The trick consists on two concentric spheres, the outern one for rad 
> lighting, and the inner one for reflection. The exterior sphere uses a 
> gray pigment function of the image_map, with high poly_wave and and high 
> ambient.

Er. Color me clueless, but how can the exterior sphere have any effect 
on the scene with the interior sphere blocking it?

-Xplo

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A 2 passes rendering, the 1st without inner sphere and radiosity saving rad
file
2nd with inner sphere and loading rad file may be

Marc


405d78a9@news.povray.org...
> Jaime Vives Piqueres wrote:
> > I started a experiment to fake the "HDRI look", and found a simple and
> > nice-looking way to do "image_map lighting" with only one radiosity
level.
> >
> > The trick consists on two concentric spheres, the outern one for rad
> > lighting, and the inner one for reflection. The exterior sphere uses a
> > gray pigment function of the image_map, with high poly_wave and and high
> > ambient.
>
> Er. Color me clueless, but how can the exterior sphere have any effect
> on the scene with the interior sphere blocking it?
>
> -Xplo
>

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Xplo Eristotle wrote:
> Er. Color me clueless, but how can the exterior sphere have any effect 
> on the scene with the interior sphere blocking it?



...tabun

-- 
Tim Cook
http://home.bellsouth.net/p/PWP-empyrean

-----BEGIN GEEK CODE BLOCK-----
Version: 3.12
GFA dpu- s: a?-- C++(++++) U P? L E--- W++(+++)>$
N++ o? K- w(+) O? M-(--) V? PS+(+++) PE(--) Y(--)
PGP-(--) t* 5++>+++++ X+ R* tv+ b++(+++) DI
D++(---) G(++) e*>++ h+ !r--- !y--
------END GEEK CODE BLOCK------

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> Quite smart idea!!!

   Thanks, but I must be not the only one trying this, as the new beta 
has some references to image_map lighting "a la HDR". In the other hand, 
it's hard to control, and must be tweaked for every image. I must create 
a macro for easy setup... some day. :(

--
Jaime

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> Er. Color me clueless, but how can the exterior sphere have any effect 
> on the scene with the interior sphere blocking it?

   Because the interior sphere has a "filter all, .99" on the image_map. 
The exterior one has a grayscale version of this image_map, with a 
exponential curve and high ambient, wich gets trough the interior 
sphere, colored by it.

   I promise to clean the code soon...

--
Jaime

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