I started the day with Out of Core, but I missed Google Body: 3D Human Anatomy in the Browser.

Over the last few years there have been a lot of papers about real-time global illumination. They always start with two caveats: no specular and one bounce. Interactive Indirect Illumination Using Voxel Cone Tracing breaks the mold and goes for two bounces! Hurray! They can also handle long-range indirect illumination better than LPVs, and it runs slightly faster. Based on their 2009 GigaVoxels work.

Out-of-core Raytracing was really hard to listen to. A big chunk of his presentation was a video of animated slides. Bad presenter, no biscuit! Even more frustrating is that the bulk of the presentation focused on the performance of his very limited raytracer. The raytracer can handle a lot of polygons, but it can't do shaders, textures, etc. When asked, he said, "Right now shading is not implemented in this project." Performance comparisons with other (more capable) raytracers are just not interesting.

What was interesting is the paging structure that he developed to make it work. The fundamental problem with GPU raytracing is that interesting scenes are multiple gigabytes, and GPUs can't handle that much data in a single batch. To over come this he developed a novel way of breaking the scene data into pages and determining which rays needed which pages. That was the interesting part, but he only spent a few scant minutes talking about it.

After that, I headed over to Stochastic Rendering & Visibility.

High-Quality Spatio-Temporal Rendering using Semi-Analytical Visibility is obviously not targeted at real-time rendering, but it seems like some aspects could be adapted. One of my favorite things about this presentation was the rich list of areas for future research.

Both Frequency Analysis and Sheared Filtering for Shadow Light Fields of Complex Occluders and Temporal Light Field Reconstruction for Rendering Distribution Effects assumed a lot of background knowledge that I don't have. In particular, all the bits about the Fourier analysis of occluder depths (which was a pretty key element!) was completely lost on me. I did find the medium frequency artifacts in the former paper interesting. Who gets medium frequency noise?!? It's always either high frequency or low frequency. I also appreciated the background material at the start of the later presentation. I'll probably harvest some of that for my VGP sequence.

The Area Perspective Transform: A Homogeneous Transform for Efficient In-Volume Queries was an interesting idea that seems to obvious to work. It takes a bunch of math operations to intersect a frustum with a bounding volume, but it's cheap to intersect an AABB with another bounding volume. Their solution? Project the points of the base (the big part) of the frustum to inifinit so that the lines become parallel (in the limit). I still need to read the paper to get all the details.

There were only a couple of papers that I paid attention to in By-Example Image Synthesis.

Techniques like Image-Guided Weathering: A New Approach Applied to Flow Phenomena are increasingly important in games. They take some examplar images to generate parameters for a particle simulation, then they use those parameters to generate new images. What's cool about this is that almost all of the computation is done to "reverse engineer" the original image. It ought to be possible to use that data (with some perturbation of the parameters) to generate new images each time the game is run. This is another one that goes on my "to implement" list.

I was really stoked about Discrete Element Textures. One of the authors, Li-Yi Wei, presented one of my favorite SIGGRAPH papers. This is "another" exemplar-based texture synthesis algorithm. Like some of the previous work they treat elements in the exemplar as units. This prevents the old artifacts of getting half a of a pebble, for example, in your gravel texture. I haven't read all of other previous work, but I thought it was pretty cool that their work also applies to 3D objects. The piles of carrots and plates of spaghetti were pretty cool.