Simulating Real Skies

radiance-general
1

Anyone know of work done on generating physically realistic HDR images of real skies?

···

--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

2

Hi Randolph,

I have been recording HDR sky images in Seattle in the past 2 years... A publicaton about the procedures and their evaluation is in review.

Mehlika

···

On Mon, 23 Aug 2010, Randolph M. Fritz wrote:

Anyone know of work done on generating physically realistic HDR images of real skies?
--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

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3

Hi Randolph,

Here is a useful sky modeling reference:

  http://gl.ict.usc.edu/skyprobes/

And for night skies:

  http://portal.acm.org/citation.cfm?id=383259.383306

Cheers,
-Greg

···

From: Mehlika Inanici <[email protected]>
Date: August 23, 2010 6:42:46 PM PDT

Hi Randolph,

I have been recording HDR sky images in Seattle in the past 2 years... A publicaton about the procedures and their evaluation is in review.

Mehlika

On Mon, 23 Aug 2010, Randolph M. Fritz wrote:

Anyone know of work done on generating physically realistic HDR images of real skies?
--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

http://www.radiance-online.org/mailman/listinfo/radiance-general

4

Hi,

There are lots of references. In my opinion, the first question you will have to answer yourself is whether you need to capture sunny skies. This is not possible without some modifications of the hardware, e.g. filters. Skies without sun can be captured with consumer-grade cameras if you have useful equipment and do some calibration.

Cheers, Lars.

···

--
Dipl.-Ing. Architect Lars O. Grobe

On Aug 24, 2010, at 1:38, "Randolph M. Fritz" <[email protected]> wrote:

Anyone know of work done on generating physically realistic HDR images of real skies?
--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

5

Thank you. The night sky model is exceptionally cool.

···

On 2010-08-23 21:17:12 -0700, Greg Ward said:

Hi Randolph,

Here is a useful sky modeling reference:

  http://gl.ict.usc.edu/skyprobes/

And for night skies:

  http://portal.acm.org/citation.cfm?id=383259.383306

Cheers,
-Greg

From: Mehlika Inanici <[email protected]>
Date: August 23, 2010 6:42:46 PM PDT

Hi Randolph,

I have been recording HDR sky images in Seattle in the past 2 years...A publicaton about the procedures and their evaluation is in review.

Mehlika

On Mon, 23 Aug 2010, Randolph M. Fritz wrote:

Anyone know of work done on generating physically realistic HDRimages of real skies?
--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

http://www.radiance-online.org/mailman/listinfo/radiance-general

--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

6

I don't know if this is directly useful, but I implemented some of the Preetham, Shirley, Smits model for sky color and radiance as a .cal file and gensky replacement. In addition (using the libnova library) the sun, moon, bright planets, and starfield can be placed properly (though the brightness of the starfield isn't yet perfectly accurate).

See the 2nd entry down on:
http://markjstock.org/radiance/

Mark

···

On Tue, 24 Aug 2010, Randolph M. Fritz wrote:

Thank you. The night sky model is exceptionally cool.

On 2010-08-23 21:17:12 -0700, Greg Ward said:

Hi Randolph,

Here is a useful sky modeling reference:

  http://gl.ict.usc.edu/skyprobes/

And for night skies:

  http://portal.acm.org/citation.cfm?id=383259.383306

Cheers,
-Greg

From: Mehlika Inanici <[email protected]>
Date: August 23, 2010 6:42:46 PM PDT

Hi Randolph,

I have been recording HDR sky images in Seattle in the past 2 years...A publicaton about the procedures and their evaluation is in review.

Mehlika

On Mon, 23 Aug 2010, Randolph M. Fritz wrote:

Anyone know of work done on generating physically realistic HDRimages of real skies?
--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

http://www.radiance-online.org/mailman/listinfo/radiance-general

--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

_______________________________________________
Radiance-general mailing list
[email protected]
http://www.radiance-online.org/mailman/listinfo/radiance-general

7

thanks.

I was thinking about a generator program, rather than capturing HDR images, but it seems that no-one has heard of one, and it sounds like there's a really interesting research project in developing one and validating it.

We might be dangerous, if we had the funding...

···

On 2010-08-24 01:24:26 -0700, Lars O. Grobe said:

There are lots of references. In my opinion, the first question you will have to answer yourself is whether you need to capture sunny skies. This is not possible without some modifications of the hardware, e.g. filters. Skies without sun can be captured with consumer-grade cameras if you have useful equipment and do some calibration.

--
Randolph M. Fritz • [email protected]
Environmental Energy Technologies Division • Lawrence Berkeley Labs

8

Hi Randolph!

I was thinking about a generator program, rather than capturing HDR
images, but it seems that no-one has heard of one, and it sounds like
there's a really interesting research project in developing one and
validating it.

Ok, complete misunderstanding from my side. Hm, of course we have the choice between various sky models and related generators, Mark's work being the latest addition. What is it that you are missing? Cloud patterns? Spectral distribution? Or the uber-gensky creating a distribution from a simulation of athmosphere, sources etc itself so that we could finally do light simulations on Mars' trabants?

We might be dangerous, if we had the funding...

Cheers, Lars.