Sunday, August 14, 2011

SIGGRAPH 2011 Trip Report: Day Four

Today had two very important events:  the WebGL BOF and the OpenGL BOF. Over the past six months, I have been developing with WebGL full-time, so I have been watching it closely (mainly through the WebGL Camps and Gile's Learning WebGL blog). The WebGL BOF exceeded my already high expectations; it was standing room only and even people outside of the room were trying to peak their heads in. There was a bit of news and lots of demos.

WebGL 1.0.1 is expected to be out in the fall to cover some corner-cases. We can also expect compressed textures soon  The most exciting news is that web workers will be able to pass typed arrays without cloning them!  We'll have to see how fast it is, but this will make web workers much more useful and suitable for a wider array of tasks like computing bounding volumes and vertex cache optimization, since hopefully thread communication overhead will not be the bottleneck. Even more interesting is that Microsoft worked on this specification. Perhaps they are adding WebGL support to IE. If they want to continue to be a player, I don't see how they will not support WebGL.

The BOF was full of exciting demos, which are on the WebGL Wiki. I'll highlight a few that I really enjoyed. Ken Russell showed a 3D cloth simulation used to flip through Chrome tabs written by a few Google interns. Very cool. Neil Trevett showed the WebGL Aquarium demo running on a Xoom Tablet using a to-be-released version of the native browser. This is super-important to me because we are banking on using WebGL to target both cross-platform desktop and mobile devices.

Mark Danks demoed My Robot Nation, which is a creative business-idea combing WebGL and 3D printing. Users model a robot using a WebGL application. A full-color 3D-printed version of the robot can then be ordered. Pricing wasn't discussed, but I wonder if this will be cheap enough to get wind-spread adoption among our youth. Mark discussed some interesting implementation details, including that the robot's mesh is never actually stored. Instead, the commands to recreate the robot are stored, which can be used to generate the rendering and 3D-printing.

Erik Möller gave an excellent talk and demo on using WebGL and HTML as a game platform. Erik works for Opera, whose browser only has 2-3% market-share, but is used on the Nintendo Wii and has more than 20% market-share on mobile devices. He discussed a platform game developed in HTML5, Emberwind, developed by three summer interns (full original version). It has the very handy feature of being able to switch between Canvas 2D and WebGL for rendering, showing WebGL to be significantly faster. Some numbers I saw showed Canvas 2D at 15 fps and WebGL above 60 fps. Part of this was due to batching draw calls together in WebGL using a texture atlas. Erik made the excellent point that WebGL has a higher barrier to entry but allows more flexibility.
This bird smelled my English Muffin

The BOF included several other exciting demos, including the BrainBrowser by Nicolas Kassis, which uses XHR2 for transferring binary data over HTTP; PhiloGL by Nicolas Garcia Belmonte; and Chrysaora by Aleksandar Rodic, which is doing the bone simulation on the server. See the wiki for the full list of talks and demos. I want to thank Ken Russell for organizing an awesome event and for giving me a time-slot to announce the call for authors for OpenGL Insights.

The OpenGL BOF was also excellent this year. Of course, the big news was the release of OpenGL 4.2. This release has a number of new features that expose hardware features, including ARB_shader_atomic_counters and ARB_shader_image_load_store. Both of which allow shader instances to communicate to some extent. Shaders can now have side-effects. GLSL shaders are starting to feel an awful lot like CUDA (and OpenCL) kernels.

GL 4.2 also introduces ARB_texture_storage, which helps guarantee a texture is complete. This reminds me of using templates for immutability in Longs Peak. I'm glad to see those API designs making their way into OpenGL. For much, much more information on GL 4.2, check out Christophe Riccio's review.

In other OpenGL news, a version of the conformance test suite for OpenGL 3.3 and selected extensions is expected to be complete in November. GL drivers have been getting much better in recent years, and this test suite is a huge step in the right direction. In his ecosystem update, Jon Leech also mentioned they are tidying up the spec to have less undefined-behavior. I want to thank him for mentioning our call for authors for OpenGL Insights.

The BOF ended with an excellent talk, Brink Preferred Rendering with OpenGL, by Mikkel Gjøl. He described the rendering in Splash Damage, including its deferred rendering pipeline, use of occlusion queries, and virtual texturing. He said OpenGL works for AAA games, and had several useful requests including a lower-level API (not the first time we heard this at SIGGRAPH); performance warnings; and display lists, which are widely used on consoles.

Full SIGGRAPH Trip Report: day one | two | three | four | five

1 comment:

  1. I love the pictures that you have taken on day four of your trip. They are amazing to see.


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