Some Actual Larrabee Information

Tom Forsyth, one of the many programmers and engineers on Larrabee, passed on this link to a lecture he gave at Stanford on January 6 for their weekly Computer System Colloquium class. At the beginning he gives a bit about Intel’s view of Larrabee and the effect of “cancellation”, i.e., it’s not cancelled, just the first hardware release is off. He notes the day-to-day work of most Larrabee developers is unaffected. I appreciating him walking through the Intel position, as I haven’t been able to find any hard information (press releases, etc.) on their site. In retrospect, rumor-mill articles like this one (which we passed on earlier, lacking any sound data) appear to have extremely little resemblance to reality.

The rest of his lecture is about Larrabee itself. Early on he talks about the new instructions in Larrabee, something like Abrash’s article but more entertaining. Around minute 37 he gets more into graphics rendering per se. I’ve been listening to it in bits, in the background.

I3D 2010 Registration Open

I3D 2010 is located just north of Washington, DC this year, during the weekend of February 19-21 (Friday through Sunday). It will be at the Bethesda Hyatt Regency, which is conveniently located right on the Metro Red Line.

The early registration deadline for I3D itself is January 20th; hotel registration at the conference discount rate of $115 is available until January 19th.

Ke-Sen Huang has added a few paper links since we last mentioned his page, though the majority are still not available from authors’ pages. Somewhat surprising, given that December 14 was the camera-ready deadline, but perhaps some people are still returning back to their universities & colleges and haven’t gotten around to putting theirs up. That said, conferences like I3D are only partly about the papers and posters themselves. They also offer a unique and wonderful opportunity to meet and talk with leading and up-and-coming researchers and practitioners. It’s a fantastic feeling to be in an area for a few days where just about everyone there is working on ideas that are of interest to you. Anyone you meet knows something you don’t, and vice versa, and most people talk freely about what works and what doesn’t. Energizing and useful. Plus, they’re just fun people to be around, at least for this nerd.

7 things for January 4th

First day of work, so here are a few from coworkers and others:

  • Naty passed on this blog post about RGBD, a compact way of storing HDR environment map colors.
  • Gamasutra has an excerpt from Game Engine Architecture, a book we’ve mentioned before. Added bonus info on the author, Jason Gregory: he was a lead programmer on Uncharted 2 (which my older son loves, as do many others).
  • Manny Ko mentioned the free program Mendeley, which he swears by for organizing his PDF collection of graphics papers. I’ll look into it once I’ve reloaded everything after my Windows 7 upgrade.
  • Physics in graphics? Here’s one person’s extensive collection of abstracts through 2005.
  • From Nicholas Wilt, interesting to hear how one brokerage firm is now using GPUs to run complex simulations for bond prices. That GPU Gems chapter on options pricing was prescient.
  • Speaking of brokers and lots of GPUs, there’s this article. I’m a little skeptical of a GPU cloud for graphics (vs. running OpenCL), since graphics cards are not quite interchangeable parts at this point. Also, CPUs don’t normally need driver updates, GPUs do. OTOY I’m super-skeptical about, I have to admit, though I’d love to see them pull it off. Anyway, fun to think about situations where network bandwidth > graphics compute power and cloud cost < local cost.
  • One more from the demoscene, Farbrausch’s The Cube – interesting effects, what looks like procedural clips and procedural surfaces using interior mapping. At least, that’s my guess. I wish they would spend a little time explaining what they did, though maybe that would ruin the magic.

7 things for December 25

A schedule for Christmas:

7 things for December 24

Here are 7 for the day:

7 things for December 23

Here come seven more, until I run out:

  • The game Saboteur on the PS3 appears to be performing antialiasing by using MLAA. This is great to know that some form of MLAA is both fast enough and high enough quality to be usable in a commercial product. I found it interesting that it is used only in the PS3 version of the game.
  • The free glslDevil OpenGL shader debugger has recently been updated. Pretty cool (though maybe not so happy for content providers): you don’t even need the source code to debug into the shaders.
  • There is a new site dedicated to OpenCL and CUDA programming: gpucomputing.net. It is focused on university research efforts, and has some heavy-hitters in the research community involved. Just begun, not a lot there yet, but you could always subscribe to the blog.
  • Here’s a short little article on texture atlassing. If you want a bit more information, read Ivanov’s article on this topic on Gamasutra, published some years ago. For even more detail, NVIDIA’s white paper is helpful. My point: if you don’t know about texture atlassing, you should. Read one of these three and check it off your list.
  • Getting the X,Y coordinates of a pixel for a post-processing pass is typically done one of two ways: texture coordinates or using VPOS. This short article gives the details.
  • You’ll note the previous two entries came from the new blog/site gamerendering.com. There are plenty of other short articles here, most with code snippets or links to other sites. That said, I’ve asked the admin for a little more attribution of sources, e.g., the figure from our book here. Hopefully fixed by the time you see it…
  • This shader code is truly amazing (from easily my favorite graphics blog).

7 things for December 22

Some great bits have accumulated. Here they are:

  • I3D 2010 paper titles are up! Most “how would that work?!” type of title: “Stochastic Transparency”.
  • Eurographics 2010 paper titles are up! Most intriguing title: “Printed Patterns for Enhanced Shape Perception of Papercraft Models”.
  • An article in The Economist discusses how consumer technologies are being used by military forces. There are minor examples, like Xbox controllers being used to control robotic reconnaissance vehicles. I was interested to see that BAE Systems (a company that isn’t NVIDIA) talk about how using GPUs can replace other computing equipment for simulation at 1/100th the price. Of course, Iraq knew this 9 years ago.
  • I wish I had noticed this page a week ago, in time for Xmas (where X equals, nevermind): Christer Ericson’s recommended book page. I know of many of the titles, but hadn’t heard of The New Turing Omnibus before – this sounds like the perfect holiday gift for any budding computer science nerd, and something I think I’d enjoy, too. Aha, hmmm, wait, Amazon has two-day shipping… done!
  • A problem with the z-buffer, when used with a perspective view, is that the z-depths do not linearly correspond to actual world distances along the camera’s view direction. This article and this one (oh, and this is related) give ways to get back to this linear space. Why get the linear view-space depth? Two reasons immediately come to mind: proper computation of atmospheric effects, and edge detection due to z-depth changes for non-photorealistic rendering.
  • Wolfgang Engel (along with comments by others) has a great summary of order-independent transparency algorithms to date. I wonder when the day will come that we can store some number of layers per pixel without any concern about memory costs and access methods. Transparency is what kills algorithms like deferred shading, because all the layers are not there at the time when shading is resolved. Larrabee could have handled that… ah, well, someday.
  • Morgan McGuire has a paper on Ambient Occlusion Volumes (motto: shadow volumes for ambient light). I’ll be interested to see how this compares with Volumetric Obscurance in I3D 2010 (not up yet for download).

Amazon Stock Market update: one nice thing about having an Amazon Associates account is that prices at various dates are visible. The random walk that is Amazon’s pricing structure becomes apparent for our book: December 1st: $71.20, December 11-14: $75.65, December 18-22: $61.68. Discounted for the holidays? If so, Amazon’s marketing is aiming at a much different family demographic than I’m used to. “Oh, daddy, Principia Mathematica? How did you know? I’ve been wanting it for ever so long!”

Shader variations and ifdefs

Morgan McGuire’s page is the only twitter feed I follow (though Marc Laidlaw’s Trog Act Manly But is darn tempting), as he simply offers up worthwhile links on computer graphics and on game design. Strangely, though, some ideas cannot be expressed in 140 characters. So, here’s our first guest post, from Morgan:

When experimenting on a new algorithm, I have a zillion variations I’m testing packed into one shader and a lot of #ifdefs and helper functions to switch between them.  Often you need the invoking C++ code to line up, and I’m always forgetting to switch the routines in both the shaders and C++ to keep them in sync…

I just realized that I can put my #defines in a header and include the exact same header into HLSL, Cg, GLSL, CUDA, and C++ code, since they have exactly the same syntax.  So I now have both C++ and GLSL files that say #include “myoptions.h” at the top.  Cool!

(Ok, my GLSL infrastructure adds #include to the base spec, but I assume everyone else’s does too).

US Gov Requests Feedback on Open Access – ACM Gets it Wrong (Again)

By Naty Hoffman

In 2008, legislation was passed requiring all NIH-funded researchers to submit their papers to an openly available repository within a year of publication.  Even this modest step towards full open access was immediately attacked by rent-seeking scientific publishers.

More recently the White House Office of Science and Technology Policy started to collect public feedback on expanding open access.  The first phase of this process ends on December 20th.

From ACM’s official comment, it is clearly joining the rent-seekers.  This is perhaps not surprising, considering the recent ACM take-down of Ke-Sen Huang’s paper link pages (Bernard Rous, who signed the comment, is also the person who issued the take-down).  In the paper link case ACM did eventually see reason.  At the time, I naively believed this marked a fundamental change in ACM’s approach; I have been proven wrong.

ACM’s comment can be found towards the bottom of this link; I will quote the salient parts here for comment.

ACM: “We think it is imperative that deposits be made in institutional repositories vs. a centralized repository…”

A centralized repository is more valuable than a scattering of papers on author’s institutional web pages.  ACM evidently agrees, given that it has gone to the trouble of setting up just such a repository (the Digital Library).  ACM’s only problem with a central, open access repository is that it would compete with its own (closed) one.  Since an open repository contributes far more value to the community than one locked behind a paywall, ACM appears to value its revenue streams over the good of the community it supposedly exists to serve.

ACM: “…essentially everything ACM publishes is freely available somewhere on the Web… In our community, as in others, voluntary posting is working.”

This is demonstrably false.  Almost every graphics conference has papers which are not openly available.  Many computing fields are even worse off.

Most infuriatingly, ACM presents a false balance between its own needs and the needs of the computing community:

ACM: “…there is a fundamental balance or compromise in how ACM and the community have approached this issue – a balance that serves both… We think it is imperative that any federally mandated open access policy maintain a similar balance… There is an approach to open access that allows the community immediate access to research results but also allows scholarly publishers like ACM to sustain their publishing programs. It is all about balance.”

What nonsense is this?  The ACM has no legitimate needs or interests other than those of its members!  How would U.S. voters react to a Senator claiming that a given piece of legislation (say, one reducing restrictions on campaign financing) “strikes a fundamental balance between the needs of the Senate and those of the United States of America”?  ACM has lost its way, profoundly and tragically.

As much as Mr. Rous would like to think otherwise, ACM’s publishing program is not an end in itself, but a means to an end.  ACM arguing that an open repository of papers would be harmful because it “undermines the unique value” of ACM’s closed repository is like the Salvation Army arguing that a food stamp program is harmful because it “undermines the unique value” of their soup kitchens.

If you are an ACM member, these statements were made in your name.  Regardless of membership, if you care at all about access to research publications please make your opinion known.  Read the OSTP blog post carefully, and post a polite, well-reasoned argument in the comments.  Note that first you need to register and log in – the DigitalKoans blog has the details:

Note: To post comments on the OSTP Blog, you must register and login. There are registration and login links on the sidebar of the blog home page at the bottom right (these links are not on individual blog postings).

Hurry!  The deadline for Phase I comments (which include the ACM comment) is December 20th, though you can make your opinion known in the other phases as well.

Amazon Needs Programmers, We Suspect

… at least judging from an email received by Phil Dutre which he passed on. Key excerpt follows:

Dear Amazon.com Customer,

As someone who has purchased or rated Real-Time Rendering by Tomas Moller, you might like to know that Online Interviews in Real Time will be released on December 1, 2009.  You can pre-order yours by following the link below.

With a title-finding algorithm of this quality, Amazon appears to be in need of more CS majors.

Don’t fret, by the way, I’ll be back to pointing out resources come the holidays; things are just a bit busy right now. In the meantime, you can contemplate Morgan McGuire’s gallery of real photos that appear to have rendering artifacts or look like computer graphics. It’s small right now – send him contributions!