| What is a shader ? |
| What do we need to render a three dimensional object; 2D on your monitor? We start off by building some sort of structure that has a surface, that surface is being built from triangles and why triangles? They are quick to calculate. How's each triangle being processed? Each triangle has to be transformed according to its relative position and orientation to the viewer. Each of the three vertices the triangle is made up of is transformed to its proper view space position. The next step is to light the triangle by taking the transformed vertices and applying a lighting calculation for every light defined in the scene. At last the triangle needs to be projected to the screen in order to rasterize it. During rasterization the triangle will be shaded and textured.
Graphic processors like the GeForce series are able to perform a certain amount of these tasks. The first generation was able to draw shaded and textured triangles in hardware. The CPU still had the burden to feed the graphics processor with transformed and lit vertices, triangle gradients for shading and texturing, etc. Integrating the triangle setup into the chip logic was the next step and finally even transformation and lighting (TnL) was possible in hardware, reducing the CPU load considerably (GeForce 256). The big disadvantage was that a game programmer had no direct (i.e. program driven) control over transformation, lighting and pixel rendering because all the calculation models were fixed on the chip. And now we finally get to the stage where we can explain Shaders. Vertex and Pixel shaders allow developers to code customized transformation and lighting calculations as well as pixel coloring functionality. Each shader is basically nothing more than a relatively small program executed on the graphics processor to control either vertex or pixel processing. |
Now then, our usual blurb: What are the major advantages of the Series 6 and 7 products? Well, feature wise we are looking pretty much at the same technology we have known for 14-15 months now. What you need to remember is that any Series 6 and 7 graphics card can achieve what a modern game expects from it. Obviously the keywords over the past couple of years has been "Shader technology." It really changed the way we look at games from a graphical "Point of View". It allows the game programmers to take games to a next level in both a visual and performance terms.
As always, that's the point where we land and quickly discuss Shader Model 3.
Talking about Shader Model 3
If you program or play computer games or even recently attempted to purchase a video card, then you will have no doubt heard the terms "Vertex Shader" and "Pixel Shader". The step from 2.0 to 3.0 was a small one and most Shader Model 2.0 games can easily be upgraded to Model 3.0, which can bring more performance to that gaming experience. DirectX 9 was recently updated and we are going to see more and more support for 3.0 Shaders.
Is SM 3.0 technology a huge visual advantage over 2.0? Nope, not even the slightest bit. Yet any technological advance is always welcome and preferred over a previous generation's development. What you need to remember about Shaders is that they can and will be used only in several critical places where it can give a performance boost, and graphics cards are all about performance my friends. Both ATI and NVIDIA now offer Shader Model 3 support in their new products - in the GeForce 6 Series and newer from NVIDIA and for ATI their X1000 series and newer.
Talking about HDR
Another big trendy implementation that will bring games closer to a movie like quality experience is HDR.
Both ATI and NVIDIA
have been focusing extremely hard on HDR. They put a lot of money into their technology to support HDR in the best possible way and they should as it's just a fantastic effect that brings so much more to the your gameplay experience. HDR is something you all know from games like Far Cry, it's extremely bright lighting that brings a really cool cinematic effect to gaming. This effect is becoming extraordinarily popular.
Valve recently released a new HL2 level in the form of Half Life 2: Lost Coast as a tech demo. Go download it as it'll show and amaze you with what HDR can do. The difference is obvious. HDR means High Dynamic Range. HDR facilitates the use of color values way beyond the normal range of the color palette in an effort to produce a more extreme form of lighting rendering. Typically this trick is used to contrast really dark scenery. Extreme sunlight, over-saturation or over exposure is a good example of what exactly is possible. The most simple way to describe it would be controlling the amount of light present in a certain position in a 3D scene.
Half Life 2 - Lost Coast level. If you bought the game, available for free on Steam.
HDR is already present in Far Cry, 3DMark06, Splinter Cell: Chaos Theory and in Half Life 2: Lost Coast. Oblivion, Serious Sam 2, Age of empires III and it will be available in Unreal 3 and likely a large number of other games. Let the screenshots do the talking.
The XFX GeForce 7900 GTX 512MB XXX Edition goodies
As you have been able to observe, our review sample today comes from XFX. The software bundle is okay, not ground breaking stuff though. Likely this is to push down the price and cost. Yet there is some software included - "3D-Edit" Video Editing suite (which no-body will ever even install I guess) and one gaming title named StarShip Troopers. Furthermore you'll find:
- Driver CD with a set of tools
- S-Video Cable
- DVI to VGA Adaptor 2x
- Six pin PSU power connector
- HDTV component output block
- Manual
There's nothing much to be said here other than it's an okay bundle and has everything included to get you going for sure. The card itself seems to be 100% NVIDIA reference based, except for a little XFX sticker and the pre-mod overclock which has been locked in the BIOS. That "XXX" clock of the card we can translate to a 700 MHz core clock (650 default) and 1800 MHz memory clock (1700 default). And that's quite something as you'll get even more screamingly fast performance right out of the box.
The hard & software bundle along with that d-e-licious graphics card.
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