Monthly Archives: June 2009

ShaderX7

ShaderX7 has been out for a few months now, but due to its size (at 773 pages, it is by far the largest of the series) I haven’t been able to finish going through it until recently.  Here are the chapters I found most interesting (click the link for the rest of this post): Continue reading

EGSR and HPG 2009 papers

Ke-Sen Huang has what looks like the full lists of papers for both HPG 2009 and EGSR 2009.  Both of these lists are only available on Ke-Sen’s site at the moment; presumably they will appear on the HPG and EGSR websites soon.  I have had high hopes for these conferences, especially given the somewhat disappointing real-time content of the SIGGRAPH 2009 papers program.  EGSR has historically had some good real-time stuff in it, and the new HPG (High-Performance Graphics) conference has a highly relevant area of focus.  So how do the paper lists stack up?

EGSR 2009 has a bunch of potentially interesting papers, including some on GPU-accelerated ray-tracing and photon mapping.  Some have intriguing titles (but no other information, so it’s hard to guess how relevant they are): Fast Global Illumination on Dynamic Height Fields, Efficient and Accurate Rendering of Complex Light Sources.  One paper I found particularly interesting is Hierarchical Image-Space Radiosity for Interactive Global Illumination (available here):  This paper extends an I3D 2009 paper (Multiresolution Splatting for Indirect Illumination) which described an “Instant Radiosity”-type approach (using lots of point light sources to simulate indirect bounces), rendering into a pyramid of frame buffers at different resolutions.  The pyramid was finally collapsed into a single frame buffer to generate the final frame.  I found the multiresolution rendering approach interesting, but the implementation was very slow.  The EGSR 2009 paper speeds this part of the algorithm up significantly, and adds some other extensions and improvements.  I wouldn’t run off and implement this paper into a game engine (it has some significant limitations, and is not nearly fast enough on current hardware), but it does suggest some interesting research directions.

What about HPG 2009, the new kid on the block?  Given the partial descent of this conference from the Interactive Ray-Tracing symposium, one would expect a fair bit of ray-tracing-related papers, but there aren’t that many: out of 21 papers, 4 papers explicitly mention ray-tracing, and 3 more deal with dynamic construction of bounding volume hierarchies (a particular concern of ray-tracing algorithms).  Many of the remaining papers deal with other (and to my mind, more interesting) rendering algorithms.  Data-Parallel Rasterization of Micropolygons With Defocus and Motion Blur appears to describe an algorithm similar to REYES (which powers Pixar’s Renderman).  There are two papers on image space techniques (Hardware-Accelerated Global Illumination by Image Space Photon Mapping and Image Space Gathering), which is a “hot” area right now following the popularity of SSAO and related techniques.  There are two papers relating to the important topic of antialiasing (A Directionally Adaptive Edge Anti-Aliasing Filter and Morphological Antialiasing).  One paper (Stream Compaction for Deferred Shading) relates to deferred shading, which is also a “hot” topic in game rendering at the moment.

I look forward to the preprints becoming available, so we can see if these papers live up to the promise of their titles (anmd perhaps discover some surprises among the more ambiguously-titled papers).

Bits of News

Just some quick bits to chew on for breakfast:

  • Microsoft announced Project Natal at E3; the (simulated) video is entertaining. Lionhead Studios’ demo is also worth a look. Somehow a little creepy, and I suspect in practice there’s a high likelihood that a user will quickly run off the rails and not do what’s expected, but still. Considering how limited the Eye Toy is compared to its hype, I’m not holding my breath, but it’s interesting to know & think about. (thanks to Adam Felt for the link)
  • New book out, Graphics Shaders: Theory and Practice. It’s about GLSL, you can find the Table of Contents and other front matter at the book’s site (look to the right side). I hope to get a copy and give a review at some point.
  • I mentioned Mark Haigh-Hutchinson’s Real-Time Cameras book in an earlier post. The, honestly, touching story of its history is republished on Mark DeLoura’s blog at Gamasutra.
  • Nice history of graphics cards, with many pictures.
  • Humus describes a clever particle rendering optimization technique (update), and provides a utility. Basically, make the polygon fit the visible part of the particle to save on fill rate. One of those ideas that I suspect many of us have wondered if it’s worth doing. It is, and it’s great to have someone actually test it out and publish the results.
  • This is an interesting concept: with an NVIDIA card and their new driver you can now turn on ambient occlusion for 22 games that don’t actually use this technique in their shipped shaders. In itself, this feature is a minor plus, but brings up all sorts of questions, such as buying into a particular brand to improve quality, who controls and who can modify the artistic look of a game, etc. (thanks to Mauricio Vives for the link)
  • Old, but if you haven’t seen it before, it’s a must: transparent screens.

Deferred lighting approaches

In Section 7.9.2 of Real-Time Rendering, we discussed deferred rendering approaches, including “partially-deferred” methods where some subset of shader properties are written to buffers.  Since publication, a particular type of partially-deferred method has gained some popularity.  There are a few different variants of this approach that are worth discussing; more details “under the fold”.

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