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Re: A natural situation

Posted: Sun Dec 29, 2013 2:19 pm
by CTZn
yonosoy wrote:Second positive (maybe now it's better to wait for the new medium and conditions). Speed: 23k samples/s Time:4h30min. Since there are no details and a propper material, till here (only 600 samples per pixel).

Image
\o/

Re: A natural situation

Posted: Sun Dec 29, 2013 2:34 pm
by yonosoy
CTZn, it's your shader (not tweaked, but the number of fbm octaves for a big volume has a great impact and not a great benefit). Hope you "come back" soon. Encouragements with those personal difficulties (simpatía> SIMilar Pathos. With the same pain or illness).

Re: A natural situation

Posted: Sun Dec 29, 2013 3:40 pm
by CTZn
thanks a lot,

waiting to get in touch with the new owner (some company it seems, currently on holidays ?) to lend them the keys over. I keep using the connection meanwhile, before a black-out of 1 to 2 weeks.

No big deal, mostly stress. By monday I'll be a squatter :D

Octaves, noted. Do it your way yonosoy, it's more than right !

e: by the way, this last pic of yours is now my desktop paper !

Re: A natural situation

Posted: Sun Dec 29, 2013 3:59 pm
by yonosoy
Thanks. Some days of analysis instead of touching bad the code (a very big suffer with so many monsters published). Really, it's a great desconsideration to take this codes and change everything without talent.

Re: A natural situation

Posted: Mon Dec 30, 2013 3:59 am
by Godzilla
very cool work :)

Re: A natural situation

Posted: Mon Dec 30, 2013 5:38 am
by yonosoy
Another one. From under the volume the situation is right too. With a sphere equation by earth and the canyons shape above.
Speed: 21K samples/second. Time:8h45m. Near 1000 samples/pixel. (more complex)
(since there are no exr, is nude, ... the shoots are taken with ektachrome and are directly indigo's output). Sometimes too strict with concepts sorry ...
clouds_in atmosphere_3.jpg
Note: the info of phase function is subtitute for a uniform one when the scene is resaved.

Some time investing in this direction Godzilla, ... thanks.

Edited.
clouds_in atmosphere_3.b.jpg

Re: A natural situation

Posted: Mon Dec 30, 2013 12:44 pm
by Oscar J
Second one has its whites a little blown out, unlike the first one (which is a winner). Great work!

Re: A natural situation

Posted: Mon Dec 30, 2013 9:39 pm
by yonosoy
Thanks Oscar agree. Less doubts in the future hope! With a high zenith could be very intense.

Edit with the exr raw solution from ´'`\_(ò_Ó)_/´'` (Zom-b gratefull).
a natural situation_00_b.jpg

Re: A natural situation

Posted: Tue Dec 31, 2013 12:06 am
by Oscar J
Clouds look just perfect. :shock: What did you do to reduce the noise?

Re: A natural situation

Posted: Tue Dec 31, 2013 12:10 am
by yonosoy
No splat filter, no downsize filter. Just the integral (beginning to learn to develop this).
Other feature difficult to see in others.

Re: A natural situation

Posted: Tue Dec 31, 2013 4:10 am
by OnoSendai
Last image is fantastic, well done.

Some points:

* Henyey Greenstein g parameter for clouds is suggested to be 0.844 in this paper: 'Exact and Approximate solutions for multiple scattering by cloudy and hazy planetary atmospheres': http://pubs.giss.nasa.gov/docs/1969/1969_Hansen_2.pdf (See figure 1)

You are using 0.353, I would suggest changing to 0.844.

* Indigo actually supports data from MiePlot. Currently I use the haze phase function for haze water vapour scattering in the atmosphere. I guess I could introduce support for the cloud droplet phase function, which would be more accurate than the Henyey Greenstein approximation.

Re: A natural situation

Posted: Tue Dec 31, 2013 4:46 am
by yonosoy
Ono, this is one of the first attempts with indigo (don't remember exactly but could be the release 3.4). The first week was focused in avoid this behaviour. Still not sure if was part of a dream, something like:
<polarization>true</polarization>
If this is too in trunk the posibilities jumps another step (glories, rainbows, etc...)
possible brewster angle.jpg
Of course at time.. too much work in perspectives...
As you can see we arrive to indigo in a non propper way (there is not awatermark at the beginning) oblige for a world of plugins of very difficult acomplishment. The respect of Indigo in format and modals is great and teach.

Re: A natural situation

Posted: Tue Dec 31, 2013 4:55 am
by OnoSendai
At some point way back Indigo experimentally supported polarisation. I took it out though as the effects are rather subtle for the extra processing and code complexity required.

Re: A natural situation

Posted: Tue Dec 31, 2013 5:39 am
by galinette
Hi Ono,

Last images are interesting for my work, as I'm struggling getting perfect high definition HDRI envmaps with direct sun & clouds. The sun is so bright that it requires ND filters with very high optical thickness of about 3 (1/1000 factor), which are never neutral despite the name, and color correction is not perfect. So I'm thinking of baking envmaps.
Which atmospheric gas data are you using (paper?) ? Would it be possible to change it in table data?

Cheers,

Etienne

Re: A natural situation

Posted: Tue Dec 31, 2013 6:04 am
by yonosoy
Hi galinette. The "scientific research" by this side is til at the initial point (it's nothing serious, only feelings).
Your work is also exciting. The polarized picture is indigo's output with indigo's medium air.
Glad to meet you, for more over is intention to publish the "discoverys". Is tablet data the application that you use for approximate the spectral data from graphical curves?
Thanks.

EDIT: Sorry galinette, now is right readed ! (exciting as Ono's work of course) The app is non free, now remembering your words...