July 2012

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In my previous blog post I mentioned the newly-released book OpenGL Insights. It’s worth a second mention, for a few reasons:

  • The editors and some contributors will be signing their book at SIGGRAPH at the CRC booth (#929) at Tuesday, 2 pm. This is a great chance to meet a bunch of OpenGL experts and chat.
  • Five free chapters, which can be found here. In particular, “Performance Tuning for Tile-Based Architectures” is of use to anyone doing 3D on mobile devices. Most of these devices are tile-based, so have a number of significant differences from normal PC GPUs. Reading this chapter and the (previously-mentioned) slideset Bringing AAA Graphics to Mobile Platforms (PDF version) should give you a good sense of the pitfalls and opportunities of mobile tile-based architectures.
  • The book’s website has an OpenGL pipeline map page (direct link to PDF here). Knowing what happens when can clarify some mysteries and solve some bugs.
  • The website also has a tips page, pointing out some of the subtleties of the API and the shading language.

While I’m at it, here are some other worthwhile OpenGL resource links I’ve been collecting:

  • ApiTrace: a simple set of wrapper DLLs that capture graphics API calls (also works for DirectX). You can replay and examine just about everything – think “PIX for OpenGL”, only better. For example, you can edit a shader in a captured run and immediately see the effect. Also, it’s open-source and as of this writing is actively being developed.
  • ANGLE: software to translate OpenGL ES 2.0 calls to DirectX 9 calls. This package is what both Chrome and Firefox use to run WebGL programs on Windows. Open source, of course. Actually, just assume everything here is open-source unless I say different (which I won’t).
    • Edit: Patrick Cozzi (one of the editors of OpenGL Insights) notes that there are several options for WebGL on IE. “Currently, I think the best option is to use Chrome Frame. It painlessly installs without admin rights, and also brings Chrome’s fast JavaScript engine to IE. We use it on http://cesium.agi.com and I actually demo it on IE (including installing Chrome Frame) by request quite frequently.”
  • Microsoft Internet Explorer won’t support WebGL, so someone else did as a plug-in.
  • Equalizer: a framework for coarse-parallel OpenGL rendering (think multi-display and multi-machine).
  • Oolong and dEngine: OpenGL ES rendering engines for the iPhone and iPad. Good for learning how things work. Oolong is 90% C++, dEngine is pure C. Each has its own features, e.g. dEngine supports bump mapping and shadow mapping.
  • A bit dated (OpenGL ES 1.1), but might be of interest: a readable rundown of the ancient Wolf3D engine and how it was ported to the iPhone.
  • gl2mark: benchmarking software for OpenGL ES 2.0
  • Matrix libraries: GLM is a full-blown matrix library based on OpenGL naming conventions, libmatrix is a template library for vector and matrix transformations for OpenGL, VMSL is a tiny library for providing modern OpenGL with the modelview/projection matrix functionality in OpenGL 1.0.
  • G3D: well, it’s more a user of OpenGL, but worth a mention. It’s a pretty nice C++ rendering engine that includes deferred shading, as well as ray tracing. I use it a lot for OBJ file display.
  • OpenGL works with cairo, a 2D vector-based drawing engine. Funky.

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Here we go:

  • Beautiful demo of various effects, the realtime hybrid raytracing demo RIGID GEMS. Do note there are controls. The foreground blurs for the depth-of-field are a little unconvincing, but the rest is lovely! (thanks to Steve Worley for the tip)
  • Books to check out at SIGGRAPH, or now (I’m sure there are more – let me know):  OpenGL Insights and Shadow Algorithms Data Miner. Five chapters of OpenGL Insights are free to read here. There are quite a few graphics books published since last SIGGRAPH, we have them listed here.
  • Scalable Ambient Obscurance looks worthwhile, and there’s even a demo and source.
  • I can’t say I grok it all yet, but Bringing AAA Graphics to Mobile Platforms (from GDC) has a lot of chewy information on what’s fast and slow on typical mobile hardware, as well as how it works. PDF version on the Unreal Engine site.
  • A somewhat older (a whole year or so old) article on changing resolution on the fly to maintain frame rate. (Thanks, Mauricio)
  • 3D printing opens up a wide range of legal issues, It Will Be Awesome if They Don’t Screw it Up gives an overview of some of these. There are a number of areas where the law hasn’t had to concern itself yet.
  • Echo chamber: stuff you should probably know about already, but just in case. 1) Ouya, a monster money-raiser Kickstarter project for an open console. Tim Lottes comments; my take is “Android games on a console? Weak.” but I’d love to see them succeed. 2) Source Filmmaker, a free film making system from Valve. People are getting busy with it.

To conclude, a photo that looks like a rendering bug; read about it here. If you like these sorts of things, see more at the “2 True 2B Good” collection.

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My schedule for SIGGRAPH so far (sans social gatherings), using this technology where you can put everything on this incredibly light-weight portable screen with an extremely high battery life (though the erase feature sucks if you use the high-contrast “ink” display mode):

SIGGRAPH 2012

I’ve tried various apps over the years and this is what works for me. On the back is plenty of room for quick notes on things to follow-up on after SIGGRAPH, if I write small enough.

Oh, and yes, Emil Persson’s talk is going to happen twice (not his fault, and I consider this A Very Good Thing), as, apparently, is the Processing 2.0 talk, also. Ah, wait, I just heard back from Andres, and the second Processing talk (on Tuesday) is cancelled.

Edits: added Fast Forward (thanks, Hanspeter). Also, I entirely forgot to look at the Exhibitor Talks, which have a few things of interest.

Oh, and here’s a neat Google Calendar thingy for SIGGRAPH 2012 that Dan Wexler pointed me at: http://skitten.org/2012/07/siggraph-2012-google-calendars/

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