X-bit labs

Wednesday, July 27, 2005

Different Shader Models Explained. Shaders: Past, Present and Future

Bit-tech.net has issued an article about different shader models used in graphics cards. The author explains the difference between early Shader Model 1.1 and the latest Shader Model 3.0. The editorial also contains information about possible mid-term future evolution of pixel and vertex shader models, particularly about the unified shader language of the Windows Graphics Foundation 2.0 API, which will be used in the upcoming new operating system from Microsoft, dubbed WindowsVista.

“So when are the different shader models used, and what difference do they make? The main differences between them can be summed up fairly easily. Each revision has allowed for the length of a shader - the number of separate instructions that can be executed - to be increased, allowing for increasingly complex and sophisticated effects to be created. The ways in which the programmers can be written has also improved - the 1.1 specification provides just for straight code, whilst the 2.x revisions allow for some looping to take please to repeat lines of code. The 3.0 model allows for dynamic branching along the lines of if/then statements in code. Increasingly smooth techniques for cutting the length of code have been made, allowing for speed improvements. Possibly the biggest single change between the 2.x and 3.0 specification is the addition of Vertex texture lookups in 3.0, which allows for displacement mapping to take place,” explains bit-tech.net.

• Bit-tech.net: A Bluffer’s Guide to Shader Models.

How to Find Dead Pixels on LCD Display. Recognizing Dead Pixels on LCD

LCD displays nowadays become more and more popular on the market and among consumers. While in general liquid-crystal monitors have numerous advantages over cathode-ray tube displays, they have their own peculiarities customers should know, especially in cases when buying a used device. One of such peculiarities is dead pixels, another is state of backlight, to name a few. DarkVision Hardware has posted an article about LCD panel dead pixels, where it explained some methods of unveiling this kind of defects.

“Once you’ve cleaned it, you can run a quick check with a free software called Dead Pixel Buddy. It’s basically a very simple file that will rotate your screen through all the basic colors. This way you can tell if a pixel on your screen is not displaying properly. One tip, you might want to get a help of a friend. Two sets of eyes are better than one especially since pixels tend to be minuscule,” says the article.

“If you do find dead pixels, don't panic yet, as mentioned earlier, a small amount of dead pixels could be inevitable but if you have a lot of them and your notebook computer is still under warranty, this may be a good time to call up the manufacturer and ask for assistance,” the author Lynn Chan notes.

DarkVision Hardware: How to Check LCD Displays for Dead Pixels.