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Photon Soup Update

Posted by timothy on from the happy-4th dept.

rkeene517 writes "Two and a half months ago I posted an article asking for spare computer cycles. I was swamped by emails and volunteers. After the first weeks most dropped out. The die-hards kept running the program and we simulated 45.3 billion photons. The pictures are here. Thanks to all that helped out. I will be submitting the images to SIGGRAPH 2005 and a paper. (P.S. Never post your email address on slashdot. I got 900 emails! ouch.)"

27 of 116 comments (clear)

  1. Never post by bert.cl · · Score: 5, Funny

    The pictures are here. Thanks to all that helped out. I will be submitting the images to SIGGRAPH 2005 and a paper. (P.S. Never post your email address on slashdot. I got 900 emails! ouch.)" Within 2 months: "The paper got a prize and I would like to thank everyone who participated PS: Never post pictures of photo's on slashdot, my webserver is nothing but photons now"

    1. Re:Never post by Anonymous Coward · · Score: 3, Funny

      P.S. Never post your email address on slashdot. I got 900 emails! ouch.

      Bah, 900 emails is nothing. I'm still wondering how they got my address.

      William H. Gates III
      bill.gates@microsoft.com

    2. Re:Never post by Sri+Lumpa · · Score: 2


      Let's just say that after that story he will find out that he didn't need to _simulate_ the 45.3 billions photons.

      --
      "The obvious mathematical breakthrough would be development of an easy way to factor large prime numbers." Bill Gates,
    3. Re:Never post by dolphinling · · Score: 2, Funny

      Looks like he still needs the computing cycles. There a client we can run for that?

      --
      There are 11 types of people in the world: those who can count in binary, and those who can't.
  2. Never post your site, either by marsu_k · · Score: 4, Funny
    (P.S. Never post your email address on slashdot. I got 900 emails! ouch.)
    One comment and cpjava.net is already inaccessible... guess you shouldn't post links either :-)
  3. Neutrinos, too by mangu · · Score: 2, Funny
    I'd be interested in the process you suggest that transforms matter into photons...


    I don't think this is possible. AFAIK, one could merge that server with another simlar server composed entirely of anti-matter, but then one would be left with a lot of neutrinos, besides the photons.

  4. Re:Freecache by Halo1 · · Score: 3, Informative

    Since freecache only caches files >5MB, this isn't going to help anything (freecache is just going to pass those requests through to the original server)...

    --
    Donate free food here
  5. Re:I missed this I guess... by gl4ss · · Score: 3, Informative

    read the fucking blurb?

    ** I will be submitting the images to SIGGRAPH 2005 and a paper.**

    the images make a nice addition to the paper.. to show that the technique actually works.

    --
    world was created 5 seconds before this post as it is.
  6. Auto-Mirror by andr0meda · · Score: 2, Interesting


    How difficult could it be to auto-mirror front page stories on /. itself?

    I mean, data-wise, local websites probably take up anything under a 100 Meg, and only go a few pages deep. The rest of it can still link to the outside world, since the probability of people following over 2 pages deep links away from the actual report is small. So the outside server could easily survive, and is not forced to switch servers just because there is ONE spike. /. itself Already takes the hit anyway, so it could easily sustain the traffic.

    It seems a bit silly to force websites onto larger bandwidth servers because they get linked to from news sites such as these. It's nice for the advancement of broadband, but it's also wastefull in resources most of the time.

    --
    With great power comes great electricity bills.
    1. Re:Auto-Mirror by Ieshan · · Score: 3, Interesting

      I'm feeding a troll, so I'm posting without bonus to lessen the ugly karma hit.

      Don't be ridiculous. Caching DOES have very tricky issues dealing with copyright infringement.

      My suggestion for Caching, though:

      Enable submitter-optional caching, don't cache sites with any ad banners, only cache a site AFTER a cache.txt file has been placed in the home directory of the site with a listing of the files allowed to be cached (check it once every 5 minutes or so).

  7. 10 fempto seconds by goombah99 · · Score: 2, Informative
    IIRC, 1 watt-second of light contains about 4xE+19 visible wavelength photons. So if the scene is illumnated with a 100 watt bulb then 4 Billion photons is equivalent to a 10 fempto second shutter speed.

    Of course if he was infact only modeling the photons that made it to the lens then the number might be a few hundred times larger.

    Thus I dont understand why this page is taking so long to load. If he had just put those photons into the optical fiber carrying my web connection I would have gotten them sooner.

    --
    Some drink at the fountain of knowledge. Others just gargle.
  8. Heh, so Java's slow indeed by vadim_t · · Score: 3, Interesting

    Computers got 3000 times faster, but Java managed to compensate for 11 years of evolution.

    The previous article says:
    Year: 1994
    Computers: 100 SparcStation 1
    Time: 1 month
    Photons: 29 billion, 29 billion/month

    Now we have:
    Year: 2004
    Computers: Unknown, supposedly 3000 times faster
    Time: 2.5 months
    Photons: 45.3 billions, 18 billion/month

    If computers are indeed 3000 times faster, or heck, even 100, you should have got 72 billion just out of one of those computers running for the 2.5 months.

    1. Re:Heh, so Java's slow indeed by Anonymous Coward · · Score: 2, Insightful

      I don't think he's computing the same scene as in 1993. It's likely much more complex. Also, more complex algorithms could be used. In other words, you can't really compare (with the data you have).

    2. Re:Heh, so Java's slow indeed by QuantumFTL · · Score: 2, Informative
      Computers got 3000 times faster, but Java managed to compensate for 11 years of evolution.

      If that's not flamebait, I'm not sure what is... Geez, how can you even say that?

      The previous article says: Year: 1994 Computers: 100 SparcStation 1 Time: 1 month Photons: 29 billion, 29 billion/month

      Now we have: Year: 2004 Computers: Unknown, supposedly 3000 times faster Time: 2.5 months Photons: 45.3 billions, 18 billion/month

      If computers are indeed 3000 times faster, or heck, even 100, you should have got 72 billion just out of one of those computers running for the 2.5 months.

      Blockquoth the old article:
      Now computers are 3000 times faster and I am doing it again only much better, with a smaller aperature, in stereo, with 3 cameras, and with some errors fixed, and in Java.


      I don't know about you, but that sounds like to me he is complicating things quite a bit. It's hard to blame his choice of Java language on the slow execution when he's making the problem considerably harder!

      Not to mention the fact that his code may not be as efficient... I can write a slow C program too if I use the wrong data structures or a bad algorithm.

      You're comparing apples to oranges here. Photon mapping is insanely complex in terms of the computational requirements, and doing 3 cameras with stereo, etc... Yeah.
    3. Re:Heh, so Java's slow indeed by rkeene517 · · Score: 2, Interesting

      Actualy the network computing started with many people rendering the image and after a month only about 5 or 6 people were following through and still rendering. Unfortunately I didn't put in a counter for cumulative CPU hours.

      --
      Inside every complex program is a simple solution trying to get out.
    4. Re:Heh, so Java's slow indeed by RedWizzard · · Score: 2, Insightful
      who says the problem scales linear? maybe it's not O(n) but O(n*logn) or something.
      It pretty much has to scale linearly to be able to distribute it the way he's doing. Also, when you think about it, he's tracing the paths of photons and photons don't really interact with each other so therefore the complexity of the problem scales linearly with the number of photons.
  9. Mirror by uss_valiant · · Score: 5, Informative

    Such a story is useless without the images. So here's a temporary mirror for the resulting images of the project:

    Photon Rendering Project: image mirror

    The mirror won't be up forever.

  10. Re:I missed this I guess... by TheGavster · · Score: 5, Informative

    Photons mapping is currently used on a small scale in some rendering engines to more accurately simulate light bounces. Its particularly useful at calculating caustics (light getting focused through a transparent medium) which can't be done by the less intensive radiosity systems. This experiment, however, seems to try to render using photon mapping exclusively. Nice idea, though not really practical at the present state of computing, given the graininess of the images and the amount of processing time. The Brazil rendering system (http://www.splutterfish.com/sf/sf_gen_page.php3?p rinter=1&page=brazil) for example, uses photon mapping on a much small scale (usually between 1-10M photons) in combination with raytracing to provide clear, realistic imagery (though not as technically perfect as this example)

    --
    "Because Science" is one step from "Because old book". Try "Because of my experiment testing my falsifiable assertion".
  11. Another copy by andy314 · · Score: 2, Informative

    All 6 images: http://ca.geocities.com/andy314_1/photons.tar.gz

  12. 650k PNG files? by fontkick · · Score: 3, Informative

    I would recommend that the submitter take down the zips and images and reoptimize them as smaller size JPGs. A 650k file is just crazy for the actual image - which is only 512 pixels wide and blurry (due to depth of field effects). Just go into Photoshop, hit "Save for web", and you can resize and change the JPG settings to your hearts content. I got one of the files down to 12k and it looks fine. These are not highly detailed images to start with. .PNG may be the format of choice for geeks worldwide, but I've always thought it was worthless.

    1. Re:650k PNG files? by azuretongue · · Score: 2, Informative

      Heck use pngcrush
      Best pngcrush method = 124 for soup_one.png (32.88% reduction)

      Best pngcrush method = 124 for soup_one_2.png (33.17% reduction)

      Best pngcrush method = 16 for soup_two.png (36.67% reduction)

      Best pngcrush method = 16 for soup_two_2.png (36.85% reduction)

      Best pngcrush method = 16 for soup_three.png (28.52% reduction)

      Best pngcrush method = 16 for soup_three_2.png (28.57% reduction)

      Pngcrush is free, open, and cross platform enough to run on those Sun SparcSataion1s he seems to be using.

  13. 1950's Kodacolor, trolls and new techniques by theolein · · Score: 4, Interesting

    Firstly, I'm kind of irritated that the usual slashdot troll crowd expends so much hatred and ignorance on a truly creative project. The technique might not be using OpenGL, DirectX or ATi or NVidia's newest cards, but that is no reason to trash talk a technique that, in a few years time, might revolutionise CGI work in movies.

    And in movie production is where this technique will most probably eventually find use. Movie studios have the budget and the server farm equipment to make good use of a time and resource expensive technique such as this.

    And they certainly would want to. The images have almost exactly the same quality as grainy 1950's kodacolor or poor images from my 1970's vintage Kodak instamatic. While adding grain to a movie is no problem, most rendering techniques used today produce surfaces that are simply too clean and glass effects that are too clear, and this immediately gets picked up by the human eye, which is very good at subliminally noticing differences in image quality. Tracing the paths of photons and their interaction through and with materials produces images that mimic reality in an excellent way, IMO.

    I'm pretty sure that a large cluster, such as the one using Apple's G5s at Virginia tech, running optimised C or C++ code would be able to produce usable footage for movies. And what's more, I'm pretty sure that sooner or later, there will be tools to make this technique more accessable.

    1. Re:1950's Kodacolor, trolls and new techniques by Hast · · Score: 2, Informative

      No, this is not a very useable way of rendering images. And he says so in the readme.

      Tracing photons is already used with the technique of photon mapping which you can look up on the net, there is a load of information available on the topic, as well as example numerous images.

      It is a pity that he did not use one of the standard scenes available to test renderers because then it would have been easier to compare the results with already existing renderers.

      The thing is, while this method has a very accurate way of simulating a scene it has a very simple scene. If you add effects used by normal photon mapping today such as sub-surface scattering (used to create realistic skin on eg Gollum) or hair/fur renderers the computational time increases to something rediculous. Since modern rendering farms struggling with less accurate simulations today it is doubtful that this particular technique is useful.

      If fact I doubt that this technique produces a result which is significantly more accurate than eg photon mapping. (Which is, again, why the lack of a standard scene is regrettable.)

      But I do agree with you that there are a lot of less than clued in people here at Slashdot who ridicule ideas they have no grasp on how they work. (And as such make fools out of themselves.) And while that may sound as a thinly veiled attack on you it isn't ment as such. If you have some spare time I recommend that you play around with coding rendering software, it's quite easy to produce a working system. And in my experience it is very rewarding.

  14. It takes more time... by fok · · Score: 5, Funny

    It takes more time to download the images from a slashdotted site then actually render them!

    --
    \m/
  15. BitTorrent download by JackZ · · Score: 4, Informative

    Have a link to a BitTorrent tracker with the images.
    You will want 'photon_soup'

    Jack

  16. Re:Not everyone who mailed him got an answer by rkeene517 · · Score: 2, Informative

    My most sincere appologies. I had so many emails that I couldn't reply to them all. I ended up putting the code on my web site, which is what I should have done in the first place. This is the first time I ever posted to slashdot and it was a learning experience.

    --
    Inside every complex program is a simple solution trying to get out.
  17. Impressive results by phamNewan · · Score: 2, Interesting

    After finally finding the pictures I was really impressed. Someone noted that rendered images are easily detected by the human eye, but these look like pictures. Granted parts of it are fuzzy, but that is part of what makes it look so real. The actual glass images look very real.

    Great job.