Tag Archives: Python

7 Things for February 10

  • The first three are from Geeks3D, which is a worthwhile site I frequently reference. First: some noise textures, in case you don’t feel like making some yourself.
  • Next, a night-vision filter in GLSL, developed with their GeeXLab tool for prototyping shaders.
  • Finally, PyOpenGL_Lab, which calls OpenGL from Python. Interpreted languages like Python are lovely in that there’s no compilation step, making experimentation much more rapid. If you’re a Perl person, there’s this module.
  • Daniel Rákos has an article about how to perform instance culling using the GPU, using OpenGL 3.2. The basic idea is to run the bounding volumes through the geometry shader for frustum culling and pipe out results as transform feedback, which is then used in a second pass for which instances to actually render. This type of technique has been done using DirectX (e.g., Froblins), Daniel shows how to do it in OpenGL and provides source.
  • Aras Pranckevičius has a worthwhile post on deferred rendering and mipmap bugs, along with some good follow-up comments.
  • John Ratcliff’s Code Suppository has lots of little handy graphics code tidbits and chunks. It’s moving here and here on Google Code, but the original page is much easier to skim.
  • Wolfgang Engel provides a nice little page of books and resources he recommends for upcoming graphics programmers, with some good follow-up comments. I hadn’t heard of the 3D Math Primer before. It gets high ratings on Amazon, and you can use Look Inside. Skimming it over, it does look like a good book, covering many topics with the space they deserve (vs. our sometimes quick zoom through them in our own book). Code snippets are also given throughout. The book mentions “The First Law of Computer Graphics,” but unfortunately the pages explaining it are blocked. Happily, I found it on Google Books: “If it looks right, it is right”. Whew, good, I honestly was concerned there was some law I had been breaking all these years.

… and I’m all caught up, my queue is empty! Well, there will be a special post tomorrow.

7 Things for February 6

With the excitement of Ground Hog’s Day and James Joyce’s birthday over, it’s time to take off the silly paper hats and get back to writing “7 things” columns. Here goes:

  • Jeremy Shopf gives a nice summary of recent ambient occlusion papers. AO is becoming the new Shadows—every conference must have a paper on the topic. Honestly, it’s amazing that some of these ideas haven’t popped up earlier, like the line integral method. If you accept the basic approximation of AO from the start, then it’s a matter of how to best integrate the hemisphere around the point. I’m not downplaying the contribution of this research. Just the opposite, it’s more along the lines of “d’oh, brilliant, and why didn’t anyone think of that earlier?” The answer is both, “because those guys are smart” and, “they actually tried it out, vs. thinking of an idea and not pursuing it.”
  • Thinking about C++ and looking at my old utilities post, I realized I forgot an add-on I use just about every day: Visual Assist X. This product makes Visual Studio much more usable for C++. Over the years it’s become indispensable to me, as more and more features get integrated into how I work. I started off small: there’s a great button that simply switches you between the .cpp and .h version of the file. Then I noticed that other button which takes a set of lines I’ve selected and comments them out in a single mouse press, and the other button that uncomments them back. Then I found I could add a control that lets me type in a few characters to find a code file, or find a class. On and on it goes… Anyway, there’s a free trial, and for individuals it’s an entirely reasonable (for what you get) $99 license. By the way, you really don’t need to get the maintenance renewal every year.
  • As you may know, MIT has had a mandate for a number of years to put all of its courses online in some form—there are now 1900 of them. The EE & CS department, naturally enough, has quite a selection. The third most visited course on the whole site is Introduction to Computer Science and Programming, from Fall 2008 (and I approve: they use Python!). There’s only one computer graphics course, from 2003, but it covers unchanging principles and concepts so the “ancient” date is a minor problem.
  • Naty pointed out this article about deferred rendering. He notes, “A nice description of a deferred rendering system used in a demo—of particular interest is the use of raytraced distance fields for rendering fluids, and the integration of this into the overall deferred system.”
  • A month and a half ago I listed some articles about reconstructing the position or linear z-depth in a shader. Here’s another.
  • It’s the ongoing debate, back again. No, not dark vs. milk chocolate, nor Ferrari vs. Porsche, but DirectX vs. OpenGL. My own feeling is “whatever, we support both”. By the way, the upcoming book GPU PRO (which also has a blog, and has just been listed on Amazon) includes an in-depth article on porting from DX9 to OpenGL 2.0. Mark Kilgard’s presentation also discusses the differences, including the coordinate space and window space conventions.
  • I love human pixels. The Arirang Festival in North Korea is a famous example, check out Google Images. But that’s just a card stunt, impressive as it is. This video shows a technique I hadn’t seen before (note that some of it is sped up—check the speed of the people on the field—but still fantastic). There are other videos, such as this and this.