GLSL

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Last month I mentioned gDEBugger being free and the joys of cppcheck. Here are some others that have crossed my path for one reason or another. Please do let me know (and so let us all know) about any worthwhile tools and libraries I haven’t blogged about – part of the reason for putting out this list is in hopes of learning of tools I haven’t heard of yet.

  • There is now a free version of AQTime, a commercial application that finds memory leaks and performance bottlenecks.
  • The Intel Graphics Performance Analyzers are supposed to be good stuff, and free – you just sign up for the Visual Adrenaline Program. I haven’t used them, but know people that have (hey, there’s Dan Baker on Intel’s page – nice).
  • Intel’s Parallel Inspector, despite its name, is particularly strong at finding memory leaks in any programs. Free month trial.
  • NVIDIA’s Parallel Nsight, also despite its name and focus of its advertising, is not just for CUDA and DirectCompute debugging and analysis, it also works on DirectX 10 and 11 shaders – you’ll need two machines networked together, one to run the shader and the other to control it. The Standard version is free, though when you sign up for it you also get a time-limited “we hope you get hooked” Professional license. Due to a currently-goofy pair of machines in my office (on different networks, and one’s a Mac I use purely as a Windows box), I haven’t gotten to try it out yet, but the demos look pretty great.
  • The Windows Performance Analysis Tools are evidently worthwhile for checking coarse-grained performance and bottlenecks for Windows programs. Again, free. I’ve heard that a number of groups have used xperf to good effect.
  • On an entirely different subject, HLSL2GLSL does a good job of translating most DirectX 9 (only) HLSL shaders to – wait for it – GLSL. Open source, and more info here, which discusses related efforts (like Mojoshader) and translation in the other direction.
  • Not really a tool per se, but still cool to see: here’s a way to find out how much free GPU memory is left for your OpenGL application. Anyone know any way to do this sort of thing with DirectX and Vista/Windows 7?
  • Will WebGL take off? Beats me, but it’s nice to see there’s an inspector, similar to gDEBugger and PIX.
  • GLM is a C++ math library particularly well-suited for use with (but not at all dependent on) OpenGL.
  • Humus points out that the old workhorse PIX now has new functionality that lets you assign names to objects, making debugging easier.
  • While I was messing with his binvox and viewvox programs, Patrick Min pointed out there’s a free 3DS file format library out there, lib3ds. I tried it out and it did the job well, taking very little time for me to integrate into my own private copy of binvox.

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While at SIGGRAPH I like to look at new books at the booths. One you may wish to check out is Graphics Shaders: Theory and Practice, from AK Peters (or just use “Look Inside” on Amazon). I received a review copy and skimmed through it. If you’re interested in programming in GLSL 1.2 (part of OpenGL 2.1), consider looking at this one. A minor problem is that it’s not quite as up-to-date as the Orange Book (now on OpenGL 3.1), but the difference in core concepts between language versions is not large. The Graphics Shaders book is full color and comes with a lot of GLSL code examples. It has a bias towards scientific visualization, though not so much that it neglects the basics. I particularly enjoyed the chapter on noise, as it gave one of the clearest explanations I’ve seen on the differences between various types of basic interactive noise functions. One or two elements in the book are a little weak – the flowcharts for pipelines are often too small and difficult to read, for example – but all in all this looks like a solid contribution to the field. Don’t expect more elaborate effects, e.g., shadows are not touched upon. It does cover the basics, plus some additional topics like image post-processing (not normally covered in texts I’ve seen). One of the authors wrote a nice learning tool for GLSL, glman, free for download. If you find you like this tool, definitely consider the book.

Another book I noticed recently is Fluid Simulation for Computer Graphics. This is a topic I know little about, I was just interested to see that there’s any book at all. It looks pretty equation-filled, so is definitely for the serious practitioner.

Speaking of fluid simulation, Intel has an article on this topic for games. One of the chief strengths of any publication is that its staff makes a decision based on merit as to what is published and what is culled. So, I have to admit to being leery of anything that says, “Sponsored Feature”, as that means editorial review and decision-making are gone. I tend to err on the side of ignoring such articles (there’s plenty to read already). That said, Intel’s had quite a number of these articles recently, including such topics as instancing, ocean fog, FFT’s for image processing, and quite a few on parallelism.

In the “clearing the queue” category of links, I don’t think I ever pointed out this handy page, which presents all AMD/ATI and NVIDIA presentations at GDC 2009.

There’s now a (not very active, but at least it exists) Microsoft DirectX blog.

On the OpenGL front, NVIDIA has introduced bindless graphics to help avoid L2 cache misses. I will be interested to see how APIs evolve, as the elements in the current APIs that are bottlenecks are not so much CPU or GPU limitations as due to the API constructs themselves.

Thing for the day: an advertisement with interesting stippling.

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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.

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