View Full Version : DirectX 10: The Skinny



okcpulse
01-01-2007, 09:53 PM
It's what made the Windows operating system the winner in the world of PC gaming. Microsoft introduced this technology in 1995 known as DirectX. DirectX is an API (application programming interface) that accelerates the performance of gaming and watching video on a PC. DirectX allows game programmers to take advantage of a set of DLLs (dynamic link libraries) to boost graphics and sound performance. And DirectX 10 will usher in a whole new era of graphics in PC games.

Faster Performance

DirectX 10 was designed to support Shader Model 4.0, new software that supports quicker pixel shading. The 3D rendering pipeline in DirectX 10 will also introduce a new feature called Geometry Shader that can perform functions on whole polygons instead of only vertices or pixels. In plain english, 3D graphics will be drawn onto the screen at faster speeds and allowing more realistic effects to occur in a game, such as fog, smoke, fires or explosions. In a waterfall simulation using DirectX 10 on Nvidia's new 8800 GTX video card, the water flowed almost exactly like a real waterfall, where falling water turns into white sprays accompanied by mist. The ground beneath the fall was displayed in a way that real-life earth looks- wet. In todays games, and even back to 2001 when Halo was released for the original XBOX, waterfalls were simple renderings of shades made up to look like water, but held solid shapes while changing gradients once water hit the bottom. The ground beneath a water fall had the same physical appearance as dry land.

Drawing It Smart

DirectX 10 will be able to avoid drawing unnecessary geometry shapes, or shapes that are still drawn even though they are blocked by other geometries. This is known as an occlusion predicate query. Basically, any shape that is not present in a game, such as another part of a room or perimeter where you are not present, will be predicated so that all the geometric shapes you see on your screen will be given all of the processing power, drawing higher resolution shapes faster. Currently, the entire map is constantly being drawn, even though you don't see the entire map, consuming precious processing power.

NVidia's New 8800 GTX

It's a beauty. NVidia's 8800 GTX and GTS will be the first card to fully support DirectX 10 with Windows Vista Display Driver Model. The inclusion of DirectX 10 will allow the 8800 GPU to share memory and cycles with the central processor, taking a larger load off of the CPU. The graphics card will now be responsible for all of the graphics payload, using the rest of the PC as backup by sharing memory with the memory modules on the motherboard. Game developers can now add new features to games for the PC that will directly take advantage of DirectX 10 and the WDDM. DirectX 10 will include backward compatibility for DirectX 9,8 and 7, although the compatibility will be beneath a layer of software that could cause sluggish performance, though such a slowdown may not be noticeable. Microsoft's new Flight Simulator X will take advantage of the new DirectX 10, which will ship with Windows Vista this month. So imagine dirt turning to mud in a game that can cause your character to slip and slide. How about virtual changes in weather patterns, where storm fronts occur randomly within a game. That is one sweet concept. And one that could produce games that can educate our children with hands-on physics. Happy gaming!

okcpulse.com - Oklahoma City's Online Magazine (http://www.okcpulse.com) - January 2007 Edition

MadMonk
01-02-2007, 06:10 AM
Not that it really affects your article but, for clarification, API stands for Application Programming Interface. ;)

okcpulse
01-02-2007, 06:34 PM
Thanks, MadMonk. I corrected the article on my website. That's what I get for staying up until the wee hours writing and doing web design!