Hosek & Wilkie sky model : solar radiance...

Practical and theoretical implementation discussion.
Post Reply
spectral
Posts: 382
Joined: Wed Nov 30, 2011 2:27 pm
Contact:

Hosek & Wilkie sky model : solar radiance...

Post by spectral » Mon Mar 04, 2013 12:51 pm

Hi,

I have integrated the new "Hosek & Wilkie" sky model (http://cgg.mff.cuni.cz/projects/SkylightModelling/) into my renderer and it works very well for the sky radiance.

Since the version 1.2a they have add the solar radiance, but the spectral power that I got is very high !!!!

I have do a test, and if I divide the solar radiance by 10000 I can see something that looks more real (otherwise I got a white disc) :
sky.png
sky.png (76.96 KiB) Viewed 8852 times
So, does someone has try to play with the solar radiance of this model ?

Thanks
Spectral
OMPF 2 global moderator

zsolnai
Posts: 24
Joined: Thu Mar 15, 2012 1:49 pm

Re: Hosek & Wilkie sky model : solar radiance...

Post by zsolnai » Sat Mar 09, 2013 11:53 am

Hit here spectral,

while I'm not an expert on this new sky model, there is an implementation of it in LuxRender (and also a forum topic). Maybe it would be of help to you. :)
http://www.luxrender.net/forum/viewtopic.php?f=8&t=8977

Also:
http://libregraphicsworld.org/blog/entr ... dome-model

tomasdavid
Posts: 22
Joined: Wed Oct 10, 2012 12:41 pm

Re: Hosek & Wilkie sky model : solar radiance...

Post by tomasdavid » Sat Mar 09, 2013 8:36 pm

I think the sun should look like white disc. I mean, in real world, it does unless you use some very heavy darkening filter.
Also, you will probably need some kind of tonemapping to display such a bright object.
(latest news, someone told me the original code had a bug that made the sun about 6x brighter than it should have been)

spectral
Posts: 382
Joined: Wed Nov 30, 2011 2:27 pm
Contact:

Re: Hosek & Wilkie sky model : solar radiance...

Post by spectral » Sat Mar 09, 2013 8:58 pm

Thanks à lot for your answer,

So, first luxrender does not implement this model fully, in fact they use an old version that does not inclure the solar radiance, only the sky radiance.

About the factor x6, your right but it has been corrected now.

So, the image I have published is not the solar .... But the whole sky ... See the paper for more ;-)

Thanks
Spectral
OMPF 2 global moderator

shiqiu1105
Posts: 138
Joined: Sun May 27, 2012 4:42 pm

Re: Hosek & Wilkie sky model : solar radiance...

Post by shiqiu1105 » Wed Apr 03, 2013 2:54 am

How did you integrated their code?

Did you use the code provided by their site? Or did you write you own?

spectral
Posts: 382
Joined: Wed Nov 30, 2011 2:27 pm
Contact:

Re: Hosek & Wilkie sky model : solar radiance...

Post by spectral » Wed Apr 03, 2013 7:37 am

Hi,

First, I have test your code and then I have write my own... because my renderer is in OpenCL and use RGB/XYZ for the sky. So, they don't provide solar radiance as XYZ/RGB yet.

Regards
Spectral
OMPF 2 global moderator

shiqiu1105
Posts: 138
Joined: Sun May 27, 2012 4:42 pm

Re: Hosek & Wilkie sky model : solar radiance...

Post by shiqiu1105 » Wed Apr 03, 2013 5:45 pm

spectral wrote:Hi,

First, I have test your code and then I have write my own... because my renderer is in OpenCL and use RGB/XYZ for the sky. So, they don't provide solar radiance as XYZ/RGB yet.

Regards
I never really understood what's XYZ space.. - -

dr_eck
Posts: 46
Joined: Mon Dec 05, 2011 7:35 pm

Re: Hosek & Wilkie sky model : solar radiance...

Post by dr_eck » Thu Apr 04, 2013 7:06 pm


Post Reply